Years ago Uberti used a funky "D" shaped cam I believe as there was a fella on another website (since gone) who chewed Mike Harvey at Cimarron up one side & down another constanly to have Uberti change the design as these cams would literally eat themselves. Maybe Abilene remembers this debacle.
I was not around for that "debacle" but have heard about it. ( It was model P hammers, had nothing to do with the conversions). I won't say the name of the fella nor will I say what Mr. Harvey's opinion of him is. I'm not positive about this, but here's my understanding. The hammers that had the D shaped cam were the "hammer block safety" type hammers, with the block below the firing pin and the linkage pin down to the safety notch. Back then, those hammers used a different bolt and trigger and hand than the current Model P hammers that are just like Colts without the hammer block. If you tried to mix the parts, things didn't work right. It was a non-issue if you used the correct parts.
Ubertis Cattleman still has the hammer block safety on many of the non-Cimarron models. But VTI only lists a single trigger, bolt, etc. for these guns so perhaps their current hammer-block-safety hammer has been changed to use the same action parts as the Model P.
Anyways, I think that's the way I heard it, can't swear to the details.