I have been looking myself. Seems the 51 merc rings with the small stainless inner ring are no longer manufactured. A few people have them in their catalogs but not available. The hagan with the big stainless ring, to me, just doesn't look right. Maybe someone will join in with a source.
Ive looked at a few late 70's-early 80's jags at the yards, the inside pair of lights has a nice small ring that might look good if you run out of options, I know its not period, but I think they look less chunky than the hagen kits. Posted using the Full Custom H.A.M.B. App!
I'm planning on frenching my lights using the stock '48 rings. I think using the later rings that recess/tunnel the lights would not be keeping in style with the "rounded" shape of the '41-'48 Fords.