Welcome to the forum BigJ - yeah, slow and sure is the ticket, no reason to rush just get it done in your own good time. Good job on the draw filing, keep those edges crisp just as you are doing. Remember to use a new part of the file for each "draw," and clean the file often so metal burrs don't scratch up the finish.
Files are such a problem these days due to ones limited choices for plain old ordinary ones, all of those Big Box store files are generally below 3rd rate as you have discovered, they stop cutting very fast. I hope one of the fellows here can steer you to a source. I found some pretty decent ones at a local Ace hardware, store owner said they were american made but had no name stamp, said he bought them years ago as part of a large lot. The Nicholson files made in Brazil are OK (not great - avoid the ones made in Mexico), and will get the job done, for draw filing a larger Single-cut Bastard is what you need.
Remember to have fun with your project - you only build a first rifle once...
dave
PS: your photography is excellent!
