Here's some info to check out, though it's also possible I'm giving you a bum steer --
I heard that mold (#38a) referred to as a T-bird or Thunderbird mold. I also understood that it was distributed by the International Thunderbird Gaming Corp., now based in San Diego. See their website at: http://www.thunderbirdgaming.com/
The T-bird in the mold looks sorta like their logo, though not conclusive.

The story about this chip mold goes like this, as I heard it: During the period of time that California Indian casinos were "pushing the envelope" in operating quasi-slot machines in a gray area, prior to the passage of Prop 1-A, they were considered unliscensed and therefore improper for the Nevada-based chip manufacturers to deal with. (Paulson, Bud Jones, etc.) When they first opened, with card rooms, bingo, etc. they were OK, and this first era of CA Indian chips WERE made by Paulson, etc...but when they were cut-off from their normal chip suppliers, they had to turn to other distributors. That's where International Thunderbird came in (I think). They were a smaller company at the time, doing different things than they do now. May have been based in Canada at one time. Anyway, I heard that they distributed chips and other casino-related products to some of the CA. Indian casinos for a while. It appears that Int'l Thunderbird has gone on to managing several non-U.S. casinos, and the CA Indian casinos have returned to the major chip suppliers.

As I said, this story may or may not be accurate. I haven't tried to check it out with them. Feel free to call them, if anyone's still there that would know about this part of their business.