If you look at the Internet Serial Number Database for Surf Champ, there are 50 submissions, which is a pretty solid sampling size:
http://www.ipsnd.net/View.aspx?id=2459

Tossing out the sample game numbers, the lowest production ser# is 5076, and the highest is 14995.

I'd guess they started at 5000 or 5001, which would put the production more like 10,000. Now, if the 1,070 was a 'typo', then perhaps it really is 10,700.

By comparison, Surfer shows about 25 submissions:
http://www.ipsnd.net/View.aspx?id=2465

Ignoring the one sample game, and the one game with an anomalous ser# (guessing it was for a Surf Champ), the reported production serials seem to span 4385 to 6496, which would suggest a bit more than 2100 produced. So maybe they started at 4000 or 4001, went to 6500 and had a couple hundred sample games. But the serial# span is in the ballpark of the reported production.

Based on this, I'd think Surf Champ was more likely a ~10,000 game production (as was Spirit of '76, for example).

I much prefer 2-player versions, when available. Set on 3-ball play, it's only one more ball per 2-player game than a 5-ball wedgehead, so the games are still quick and keep people's interest.

They are more challenging to find too, so from a collector's perspective, that's part of the fun.

And if you work on them, the backboxes can still be maneuvered on your own for the most part. A 4-player backbox is a two-person job.

Usually better artwork on 2-player games too, since they didn't have to sacrifice space for more score reels. And they didn't do funky scaling on the size of the artwork either (the 4-player versions often seem 'small'). And the stencils are the same between the 2-player and 4-player backboxes, which leave the 4-player versions' artwork a bit 'short' on the sides.