I believe,,,,,
that only the 22 Short would chamber,,still bad thing to do. I would not leave the Winchester barrel marked with the 'previous' chambering. Easy to mill out and restamp. Once relined,,,I'm not too worried about "origionality" of the Winchester 69A. I'm still thinking of this project....and if a CZ 452 were to pop up at a good price it could put the Win 69A back in the "restoration" slot like several others I have.
I am 54 years old,,have owned hundreds of firearms,,but always thought the 69 and 69A were super practical 22 rifles, and worthy of any restoration they might need. I haven't counted recently,,but I think I have 8 of them. Some are in 95% plus condition,,othes will be fun shop projects whenever I get to them. There are 2 Win 56's in 22 SHORT [only] in the safe also, waiting for some restoration. Also have a Win 75 Sporter I picked up a few months ago, with some SUPER wood grain. Someone had sanded the stock, but enough of the checkering remains for a friend of mine skilled in checkering,,to be able to 'accurately recut' the exact same location and restore to even better than origional checkering [sharper points,,defined lines, etc]. It has Weaver scope bases,,the front drilled and tapped to the barrel as was 'accepted' back in the 50s'. At least is is true to centerline,,what with some fine old bolt 22s being POORLY drilled and tapped for scope bases. This Win 75 Sporter has been altered enough that any finishing I may do will not 'hurt' the collectability,,as the 'collectablity' has already been pretty much done in by a previous owner. The bore is excellent, the metal is perfect,,front sight hood 'still there', so this 75 sporter will be a really fun project to 'make right'. If a previous owner had not cut the forend for a black forend tip, I would attempt to restore the rifle to 'origional'. With the forend walnut missing, this stock will have to keep it's added black forend. It had white line spacers added to the buttplate, pistol grip, and at the black forend attachment joint, but at least these were easy enough to remove. Two sets of eyes are necessary for the forend white spacer to be removed,,,,one set on each side guiding a coping saw blade down the middle of the spacer as it is cut. The remaining white spacer material can then be ground off, and the black forend reattached to the stock. The origional buttplate and pistol grip cap are thankfully still there.
Alan in GA.