Not a solution here but I "triple-ized" an old SR/Sugino 110/74 crankset to be a super low Q fix gear. Three rings so I could have three very different gears for mountain up, down and flat with three very different cogs on horizontal dropouts. I did not use the inside 74 BCD holes. Instead I spaced the third ring outside the usual outer ring. (No FD and perfectly straight chainline so being very close the crank is just fine. And crankset sits inboard that much more. Knees love it.) To do this I went to Ace Hardware and bought (IIRC) 8mm flat head screws and good looking SS cap nuts. These bolts were only to provide the "squeeze". The key element to getting bolted chainring assemblies to behave, not creak and not slowly self-destruct is to have a tight, near press fit cylinder inside the crank and ring holes so nothing can slide around. To do that, I had sleeves machined to the exact 10mm (again, IIRC) of the bolt holes and a looser fit over the 8mm bolt. (The material is absurdly exotic - titanium! But only because TiCycles' Dave Levy did the work and had the perfect ti tubing on hand to start with plus all the ti machining equipment since ti bikes is what he does.)