Rusty, weren't you having some concerns, finding a carry gun recently? It may be closer than you think. With a good holster, you could have your new carry gun in the model 13.
Any good gunsmith should be able to cut the barrel back and re-cut the threads for the choke tubes. I plan to have my shotgun cut back to somewhere around 21", then re-threaded. On a barrel with the vent rib, you just have to be sure to cut it through one of the bridges, under the rib.
I traded for an 870 this week that had a stuck choke tube. I didn't think I'd ever get the thing out and figured that it would be ruined when I did get it out. I finally got it out and it turned out that the choke tube was stuck with old oil or something similar. I took some degreaser and...