[The 39 action is too short for the 22 WMRF cartridge.]
[However, if they would increase the size of the action proportionately, to the size of the 22 WMRF cartridge,]


No, it's long enough.
Granted, the internals need repositioning/reshaping, and the mag throat bored wider with an attendant wider mag tube/guides/etc, but..........

If I were re-engineering a gun in stainless, I'd sure look at some internal alterations, as well.

.


It ain't no fun, when the rabbit's got the gun