While you have the special lit, go to the back of the machine and at the credit unit, you'll see 3 free-standing switches. Just adjust all 3 to be closed all the time. After doing this, hit the special target to see if it works. Closing all 3 switches will also put the game on free play where you won't have to keep hitting the dime switch on the door, hope this works for you. If the credit target still doesn't work, report back and we'll move on with that.
The 10-point-when-lit sling alternates with the other side upon hitting anything worth 1 point. Look for the 0-9 unit in the head and while hitting something on the playfield worth 1 point, watch to see if this unit is stepping up. If it is, remove the 3 screws on the unit that are facing you. This removes the spring-loaded contact wipers and makes for easy access to cleaning the rivet board. Once cleaned, take just a few drops of 3 and 1 oil and smear on the rivets, this will make the unit step nice and snappy. Once done, re-assemble and make sure the contacts are sitting squarely on the rivets, (while the unit is sitting idle). The alternating relay under the playfield, (alternating this feature on the playfield back and forth), is driven by this unit. If the unit is NOT stepping at all, check the coil making sure it's good and is connected, then clean and check all switches on the 1-point relay in the head. There are 5 or so switches on this relay, 1 of them is to step up the 0-9 unit.
The 1's score reel appears sluggish probably due to grime build-up. Very common problem, particularly around the 9's digit. It will need to be taken apart and cleaned up. Don't let this task intimidate you. After sliding the score reel out of the housing, it's just 3 screws to remove the actual reel. There's a small printed board there to clean also. Make sure when re-assembling that the contact on the circular leaf switch is closest to the number 2 digit, (or you won't be matching on the right number at the end of the game). Also, be careful sliding the unit back into the housing from making contact with the backglass.