Good to hear from you again, buddy!
The idea of 3D-Printing masters indeed has some benefits, most notably improving the symmetry of my parts - left and right wings on each aircraft, for example, perfectly mirroring each other. However, that's just not (any of) my most urgent problem(s) - which is, first and foremost in the production casting: a need to eliminate so much fine, manual work there, which causes numbness in my fingers/hands.
The masters are the easy part - in fact, I have quite the backlog of Masters, already waiting to go! And even for all-new masters, it's doubtful how much time 3D-Printing could save me - for multiple reasons:
1) The "buffing-out" you mention is not nearly as simple as it sounds: again, it would destroy the fine details - tiny engine cowling vents on my HSS SeaBat helicopter, or the canopy on my AJ Savage, for (just two among many) example(s), would be have to be reconstructed virtually entirely, by hand. And that's after all the fine, manual work to get in there, and scrape/sand - don't forget, you're working at 550-scale - to begin with. So, that's more than halfway back to Square One, to complete the Masters, right there. If there is a single Master I am considering, for which 3D-Printing looks most promising, it would be something of very unique shape yet all-smooth surfaces - I'll tell you right now: a Fairey Gannet, in 550-scale. But, even so:
2) You're still not counting all the 3D-CG Work - you skipped this entire, First Task, by starting at "(3D-)print it out" - and, to be any GOOD, the Computer Work obviously will require substantial effort: not only all the same research currently required, but then creating the entire, 3D (TIN, or whatever) File - meanwhile, such intensive hours at the computer, will in short order also make my hands go numb - now for the Mastering as well as the Production! Unless I'm going to buy already-finished 3D-CG files for each desired Master (which, I don't even know where - much less, how I could afford - to do that), from someone else. Speaking of which:
3) The Startup Costs to begin 3D-Printing - not only for the hardware (including a new computer), the material(s), and yet more workspace (which, fortunately, I have but will take some time to get clear), but also the Learning Curve to get it all up and running well - are clearly going to be substantial: again, costs that (whatever actual) help just on the masters could never possibly justify.
All of which can be put simply another way: the Masters are just not what I need help with, at the moment. What I need 3D-Printing (or any other suitable technology) for, is the Mass-Production - again, for which 3D-Printing is just Not There, yet.
Of course, you know what's going - eventually - to happen: that when 3D-Printing finally becomes suitable for Production in 550-scale, it will also be able to do the Masters, too - so, it won't Rain, but it Will Pour! (Anyway, that's what I'm Counting On - for when I get too old to manually do- or see anything small, whatsoever...) Seriously though, that IS why I continue to watch with great interest, how 3D-Printing is doing, with every passing day.
So, stay in touch - and Keep Me Posted on anything(s) you see, buddy!