Don't waste your money on a "Blueprint"... you will get nothing from it unless you are building a top-of-the-line benchrest rifle... and M-70s are very hard to "print".
I don't think they are any harder to print than a Remington..just a little different, being a flat bottom receiver. That said, They don't seem to be as bad as a typical Remington either, in terms of "needing" printed. Also, while others may well have had a different experience, I've not seen the need to bush the firing pin hole on them either.....the fit must be better than most Remages.
If money is a concern, I'd come nearer to just truing the action face and leaving the rest alone than I would on a Remmington, too. Sure...it won't hurt to do it, but it's hard to tell the benefit of completely truing one that may only marginally need it to begin with, even in a full blown BR rig. IME, you can kinda decide how good or bad yours is by how much the action face is off. I've read that Winchesters are machined in a single setup in regard to the action face, inner lugs and threads. So, if the face is true, the lugs and threads should be about the same. I don't know if that's true or not but experience with them leads me to believe that it's at least plausible.
Again, if you get very involved in labor and money spent on the action, then just selling it and building a custom begins to make more and more sense, with every step.
Bottom line, IMHO, is true or check the face...if its far off, then decide which way to go from there. But, unless this is a competition gun, I don't believe you'll see much if any return on your money spent here. There has to be a pretty big issue for it to show in a varmint rifle. The barrel is the heart of a good shooting rifle. Keep in mind that when you true the inner and bolt lugs, you reduce primary extraction. Again, this is another area where Winchesters don't seem to often be plagued with problems like a Remington is...but start cutting the lugs and you may create a problem...and open up another can of worms that cost money to fix.
Can you tell that I kinda like Winchesters? Honestly, they're not bad. If parts availability were equal to a Remington, I'd probably say that they are a better overall platform than a Remington...
A lot of smiths aren't tooled up to work with them and some are just set in their ways, but they're a good gun.
If there's an area that I prefer a Remington over a Winchester it's probably the barrel tenon is 1" on a Winny and 1.0625 on a Remington, but I've built several Winchesters and loaded them hot without issue.