You are on the right track.  Give it a try and tell us how it comes out.  By the way, are you using 308 or 311 bullets?  Have you slugged your barrel?  If not, I would and then use the bullet that matches your bore diameter.  The 311 bullets worked the best for me in the original barrel, then the 308 when I rebarreled to get better accuracy.  However, I'm now using IMR4350.  For some reason, it seems more available than other powders.

Hi, and welcome to the wonderful world of Krags! 

I would save the 4064 for use with 150 to 165, or even a 180 grain bullet.  The reason you down find much load data for 4064 with a 220 grain bullet is because, as I stated on another thread - 4064 has a burn rate that is too fast for heavier bullets, just as 4350 burns too slow for a lighter bullet.  The standard loading for 220 grain bullets is 40.0 grains of 4350.  This is about as close as you can get to the original .30 US (30-40) ball loads.  4064 is a great powder, and I use it in my M2 Ball (30-06) and 7.7x58 mm loads, as well as 165 grain bullets for my Krag sporter. 

For what it's worth, powders, primers and bullets are starting to reappear on store shelves.  I just picked up a bunch of powder 2 weeks ago.

I hope this helps!
Paul