Do you plan to use the American or Italian add-a-ball system?
American: Ball Count unit steps both ways, ranges from 1-10 (plus game over)
Italian: separate "Lightbox Advance" unit holds 0-5 extra balls, indicated by 5 anonymous but similar objects on the backglass, standard Ball Count unit only steps one way

Team One has the American system, which is easier to implement and has the advantage that one can win more than 5 extra balls when the Ball Count unit is low enough. See Federico Croci's book on Italian pinballs for full information on why the Italian system works as it does.
.................David Marston

The end-of-ball logic driven by the trough switch would change very drastically. I hope to have a seminar at Pintastic New England 2022 that will address some of the differences in replay vs. AAB.
.................David Marston

Do you want to have scores of 200,000 and up show on your Team One (or Wizard)? Watch this video:

Dave Metrando and I present the thought processes and what to look for on the schematic. If you can do the Wizard conversion, you probably have the skills needed to set up the combination of Add-A-Ball Mode and super-high scores.
.................David Marston

I think Brian Hawkins and I will attempt to do the mod as well. From my inspection of the Team One schematic, I recommend that you plan on leaving the Play Mode adjustment plug in the Add-A-Ball position, and break out the 100K step-up as discussed in the seminar. Choose which function (Wow Count or 100Ks) will be on the new stepper unit based on what stepper you have available.

Here are some observations specific to Team One. The general setup of Team One is very similar to Neptune (but simpler) in the areas relative to the mod. One notable difference: the Ball Count Unit on Team One resets to the zero position and steps up ball by ball, with Game Over being at step 6, as it would be on a replay game of that era. The lights have been reversed, as can be seen at 4A to 4C on the schematic.

AX and JX are interlock relays that have the same function as discussed in the seminar. The AX Reset line can be seen at row 14 of the schematic. It's the same as Neptune except that the Ball Count Unit must be at 0 rather than 6. The new stepper will need to have its zero-position switch added in line as discussed beginning at 32:25 in the seminar video.

Adding wows, and the associated knocking, would still be handled by the orange-blue wire seen at 9E. That wire goes to the add coil on whichever unit you designate as the Wow Count Unit. The carry-over from 10Ks to 100Ks is the white-red wire seen at 10E. That wire goes to the add coil on whichever unit you designate as the 100K Unit, and also to JX to allow flexibility of score awards, as discussed in the seminar. The adventurous modder who has a spare interlock relay in stock could also have differing score levels in the 200K range by cascading JX with another interlock relay. With this extra mod, you could have extra balls awarded at 70K, 150K, 240K, 340K, 440K, etc. as an example.

I suppose you could do the cascading interlock relays without the additional stepper unit if you don't expect scores to get very far into the hundred thousands.

Many of the other pins in the Play Mode adjustment plug pertain to the outlandish giveaway of points associated with Novelty Mode. These would thwart the designer's intent if applied in Add-A-Ball Mode, and that's a separate discussion about how generous you want your game to be.
.................David Marston

Quick answers:
It would get you scores up to 999K, which is probably enough. The add 100K function would be using the white-red wire I already mentioned. If you want end-of-stroke functionality, note that this new reel would be driven off relay L (same as the 10K reel) for end-of-stroke purposes.

You could probably think of some creative uses for the 9th position switch on the reel. Like add a 1 million interlock relay that works like JX and lights the "1,000,000" light in the backglass. If you do that, you have to reset the interlock parallel to resetting JX.

Driving the lights off the board should be fine.

The part that needs some design work is resetting this new reel. Note that unlike the stepper-unit subtract coil we discuss in the seminar, you must run the add coil upward to zero, and have a switch that closes at zero rather than opens, plus the other zero position switch that opens to stop pulses from going to that reel. All of that must be isolated from the logic that adds 100K during game play (i.e., no back paths through the reset circuit). That may very well push the situation over the edge and force the splitting of AX into two reset relays, as we mention in the seminar. Splitting AX would mean additional design work; I think you want the one doing score reels subservient to the "main" AX, but I haven't worked through all the implications.
.................David Marston

As you can see, each score reel has its own switch on AX for the reset function. This is to prevent inadvertant scoring during game play. The reset line for each reel must be isolated to avoid back-paths.

If you convert JX to be the 1 million relay, then you can only set thresholds for wows awarded on score to a particular 10K increment (or two) that would be the same for each 100k block. You can't use the disc on the 100K unit for different scoring thresholds because it is in use driving the lights.

I like the idea of a K relay for the 10K reel. But if you're open to the idea of adding more relays, think about splitting AX first. Another strong consideration is leaving JX to do what it currently does and adding a new interlock relay (call it MX, say) for the million point light.
.................David Marston

Dave Metrando and I discuss this issue starting at 36:00 in the video, but we don't give details about splitting AX into two relays.
.................David Marston

You can play this game at Pintastic New England Sept. 7-10.
.................David Marston