That TM is the first approach that came to me, though it might be easier to find the 45C carbine (some are still avail. new?) and go that way.
The 're-machining' thing is a bit overstated (though it is something that can intimidate a guy, I know; no stone here), it is a simple hand turned 'rechamber of a few thou' on the neck of the chamber, which was usually a bit too tight for an optimum cast bullet dia. You can just neck turn some brass, too, and accomplish the same thing of bullet fit. Where can a guy get a 38-55 for this kind of money (but you do have to find somebody who wants to get rid of one!)
It is to bad they didnt make them in 32-40 as a Target Model, as that caliber is what mostly replaced the 38-55 in target circles (less recoil, thus less fatigue and better offhand scores in the course of a match). However, the 30-30 can, and has for years, proven itself every bit the equal, and more, than the venerable 32-40.
BTW, I like the looks of that 'shorter 45 Carbine forestock on even the long barreled 38-55. I think if you got the 45 Carbine and have the factory fit a 30-30 barrel to it you will be very happy (get the front sight too) and you would have no trouble selling that 45C barrel here (though you really should keep, and shoot it).