The plumbers cloth is more well known as "Carbon Felt" and is very much available in many types of sizes from big rolls to small squares of 5x5 inches for 8 or 9 bucks on evil bay. Home Dumpo charges 24 bucks for the same 5x5 square you can get on evil bay for 11 bucks. Been used for all the homemade alcohol stoves. I use a thin strip in a brass tube and a cork as my lighter and also to squirt the priming cup as the felt makes it poor more slowly and is easy to control how much you let come out.
The 'step' on the No.7 case is what restricts it but with the 80 and 71 the regulator stem slopes down and doesn't jut out horizontally as the auto-pricker 80 (No.7 type) does. There's more clearance as a result to get those stoves in and out. A Radius 42 is a shorter stove and is the easiest of the bunch to accommodate in that military issue case. John
