harleybug,
There are supporters for both sides of the decision regarding standard size and oversize taps for re-cutting threads in some actions. Suffice it to say that most folks don't think that Remington threads are straight so they opt to re-cut them completely.
In general though, the process should start with the bolt raceway, making sure that it is true and straight before proceeding with the reamer and tap mandrel. In essence you are trying to get all of the important surfaces either parallel and or perpendicular. I'm leaving out all the specifics since it would entail a lengthy dissertation which you should have already read and understood.
Some of us use indicators to get the action aligned in a lathe in order to cut all the surfaces. We single point the threads instead of using a tap.
Now, you might consider this. By the time you buy all the tools and paraphernalia needed to perform the blueprinting, you could actually afford the very best action which will not require any work at all except for maybe a quick lap of the lugs. This might be a good idea from the standpoint that you will already have a better receiver to work with than a blueprinted Remington and you will have saved yourself the necessity of buying more Remingtons in the future in order to justify purchasing the tooling in the first place.
Just something to consider.
Regards.