Identification help.
 

I was at an indoor flea market a couple hours ago and see this yellow commuter of style bike with no marks on it as far as identification goes. The brakes have synchron on it and the shifters are Shimano. What has me really confused is the fact that itss a 10 speed and the larger crank gear is Skip tooth and the smaller gear is not as well as the rear cassette / Freewheel. skip tooth on the 2 larger gears, regular teeth on the smaller ones. It has a BMA certified sticker on the seatpost tube but nothing else as far as markings. My understanding is that skip tooth gears were more or less not used after the 50s. I was wondering what information anyone has pertaining to anything I've said before I talk to the guy about purchasing it.

Altenburger made a Synchron brake. Don't know what you might have been seeing with the skip tooth unless something during the bike boom had a crank like that. Shimano, maybe. Sounds like something they'd do. I know Shimano made freewheels that had skips on the large cogs. This pic is a Shimano FFS freewheel.
http://thumbs4.ebaystatic.com/d/l225...IusqbxLEmA.jpg

Another that is a conventional Shimano.
https://farm6.staticflickr.com/5835/...e42a6db2_b.jpg

BMA would be U.S. production by someone like Huffy, Murray, etc. Probably a low end bike so unless it's very cheap you might want to save your money.

Thanks for your help. I was thinking I wouldn't offer any more than $30

I'm sure the freewheel is from Shimano, as thumpism suggests. Older Shimano wide-rage freewheels used skip-tooth large cogs, to aid shifting. This is not the same as the older skip-tooth single speed and track drivetrains, which used 1" pitch chain. AFAIK, there were no derailleur systems that used 1" pitch chain.

Re: the brakes. "Synchron" brakes were the original dual-pivot calipers, developed first by Gerry Burgess in Britain and licensed to Altenberger and Weinmann, so you may find Synchron calipers from any of these three companies. Interestingly, dual-pivot calipers were only found on low-end bikes until the early 90s, when Shimano started marketing mid and upper level dual pivot calipers. Here's the Gerry Burgess version of the Synchron caliper:

http://www.os2.dhs.org/~john/gb_dual-pivot.jpg