Mike, I've reread your post several times and I believe I understand most of it. I really appreciate how much time you took to answer my questions. I still have a couple of questions though.

In your post you say the bases were skim milled to be parallel with the barrel flats. Just to make sure does this mean that the front base with dove tail installed is skim milled to be parallel with barrel flats? and the rear base is also installed and skim milled. Skim milling is only to make the top surfaces parallel to the barrel flats but does not necessarily make the front and rear bases the same level and I assume the wouldn't very often be at the same height?

A second question. When you determine the length of the feet or foot on the rear ring do you basically just use a depth gauge and insert the gauge in the slot until it hits the bottom of the base or the top of the barrels? Then the feet are contoured to the shape of the barrel and made to the length of the above measurement?

And last for now, I am still a little unclear how you would actually scribe the line on the rear foot to determine the location of the slot for the slider. I understand the concept but am unclear how you actually do this? Do you remove the slider and springs and somehow insert a scribe from the rear of the base? or do you remove the slider and springs and come in from the side of the base to scribe the line? Or could you just leave the slider installed and use the slider itself with some smoke and let the slider mark the line to be scribed? I'm just not quite getting how this is actually done.

Again, thanks for all your help. There just isn't much information out there on how this is done and while I don't mind learning through trial and error it can be frustrating. Sure helps to get some good information on how it is done.
Ron