Muffler ID help

[ARCSinAK]

I purchased this muffler from the used parts forum with the intention of using it for my 3.2 euro motor at some point. The PO had no information as to the fabricator or brand. There are no part numbers ETC. MK? Custom 1 off? Seems to be very high quality stainless and clean welds.
.Does anyone recognize this muffler or know what engine it was intended for. The exiting pipes are larger than I predicted nearly 3” ID. I was thinking of trying on my 2.7 or 3.0 but not wanting to lose power.

Thanks for your time.