Yes, as Fox Mike posted, no problem.
1. All parts will swap, there was no machining of the frame to make the conversion. Swap all the parts except the cyl hands. They are the same part whether converted or not, but they are fitted to the cyl for proper timing.
2. Yes, the '72 model will then be safe with all 6 chambers loaded.
3. If you prefer the cool wide spur hammer in the '68 model, no problem: buy another wide spur hammer from Ruger or Brownells for a current Bearcat. The retrofit parts are the same parts used in the NM Bearcats that are made with the transfer bar. (In fact any NM Bearcat can have old parts installed in it and turned into an old model, only safe with 5 loaded.)
You will need to make one simple modification to the NM wide spur hammer to work with the old parts; file off the step on the hammer face so the hammer will reach the firing pin w/o a transfer bar installed.
Here's my OM Super Bearcat with NM Super hammer. I'm not a grip maker, but I designed and made my idea of an improved but factory like grip for it. Something to fill my hand a little more on this diminutive Ruger SA that still had a traditional look the same as other Ruger SA grips do. I installed the current small Bearcat medallions for a factory look but relocated them higher and moved forward for correct proportion. They appear and feel like standard Ruger grips on all other size SA Rugers. They still need a final sanding and coat of oil.
