It almost looks homemade to me. I say that becuse the rounded edge at the bottom, and straight edge up top, both on left of tranny, look wavy and notchy.
Not knockin the work, just doesn't seem like other tmaxx parts out there.
I will look today. Ue, dynamite, flm, and a bunch other companies flooded the tmaxx market early 2000s. Alot of products are no longer and some companies even went under.
Flm also moved to motrcycles. They do a few car parts and motocross I believe.
This chassis?
https://www.ebay.com/itm/185119077273