I have converted some of my guns, none of which were collectors items. But, I have a shop and can do things myself. With the price of skilled labor conversions are just not worth it. Bottom line prices, probably, re-chamber $150, barrel $100-150, fit barrel $50-100. $300 min. Completed value maybe $600. Nice model 28-2 value $600. I recently bought a 41 mag for $700 plus FFL fee. You could sell the 28-2 for $600 and toss in $300 and shopp around to get a shooter 41mag, dies, brass and bullet mold.

That said I have a slightly freckled 28-2 that is going to become my nephews 45 acp/colt. $500 28-2, $100 44 mag cylinder and a $100 45 barrel (could sell for more though). Sell 28 barrel and cylinder, own tools and reamer. Factory, S&W 45 colt 800-1200. . Free labor means low cost carry shooter for nephew who works and plays outdoors in Alaska.