Thanks for all the input guys and Lou, thanks for the very detailed specifics. I have some of the later Fox engines and just had never seen one that did not say "Fox" on it somewhere, even though it was obvious that it was. The lack of designation is what made me think it was a private label deal.

The carb adapter is definitely a home-brew piece.

I mounted this up in my test stand and ran it on a MA 10X6 with Sig Champion 15% enriched with a splash of additional castor. I fired it off rich and gradually leaned it out to a couple clicks rich of full beep. I swear this is the loudest 40 2C I have owned. Swapped in an OS A3 plug and it idled and transitioned very nicely, carb is set one notch lean on idle. Did not get any tach readings as the battery took an inopportune time to croak. I'll be swapping on a correct carb in the future. As it runs so nice right now, the Perry can stay for a while.