91/30 rear band/sling swivel conversion to M39 finn style

I am trying to set up my 91/30 to have a front sling swivel like the M39 finn. On the rear band and directly under the barrel.
Does anyone know of a current rear band with a swivel that may fit?

How much bigger is the M39 rear band. I could make the M39 rear band fit I guess?

My End goal is to locate a more useful sling swivel for shooting in matches. I would like to use a GI web sling.

My next solution is probably just buy another rear band and weld on a sling swivel from something in the parts bin.

1) No, there is no way an M39 band will ever fit a 91/30.
2) No, I know of no aftermarket product that is a drop-in fit for what you are asking - most ppl find the dog collar system to work well enough.
3) If you weld on a swivel, that may work, but most types of band are springy and are meant to expand in that area to they keep a tight fit. It you weld on a swivel there, they may either not go on your gun, or potentially end up being too loose. One possibility would be to flip it upside down and have the expansion joint on the top of the handguard.
4) I don't advocate that you bubba your rifle, consider not doing this.