One of these was listed on ebay for 29.50 http://www.ebay.com/itm/CWT-Patriotic-Tradesmen-Currency-One-Cent-/130557555344#ht_703wt_800 but I don't think it sold. Basically this is a Civil War Token, and uses the Fuld Numbers to identify the obverse and reverse, and rarity and value can mostly be derived from that. But I am no expert, so someone else may chime in on this.
You have a Fuld 202/434 a or b Alan. "a" denotes a token in copper, and "b" a token in brass. The copper variety is very common and is classified an R-1 (over 5,000 known), but the brass variety is much scarcer at R-8 (only 5 to 10 known). Can you tell if yours is copper or brass? Bruce
It looks copper in the pic Alan, so if it is it's a commom circulated CWT. I'm not really up on the values because I haven't collected them in a few years. I'd guess 20 to 40 bucks would be a fair price, but maybe somebody else will check in later with a better sense of value. Bruce