Barrel swap on model 61|Winchester .22 Rim Fire|Forum|Winchester Collector

 I have acquired a model 61 that has been “messed with” as some would say. At some point in her life the barrel was shortened to a little over 21 in. with no front sight or dove tail installed, the rear sight removed and dove tail plug installed. The receiver is D/T with weaver scope mounts installed. My question is, having access to an original barrel, what issues can I expect in replacing the barrel? Would head space be a problem?

  I plan to install a vintage Weaver scope but I would rather have the iron sights available also. The full length barrel would also be a plus.

Mike