Tim, Tim, Tim..... I'm shocked. You and I know that "a good couple hits with a hammer" means light taps that just move it enough to get it out but some folks may take this to mean "whack it like a 6 inch rail spike".....

I used to tap it off like you using a hammer but I found that I bent the odd prop screw and that the end would get peened down and not let the screwdriver in any more. Now I use a vise to push them off instead. I insert the prop screw all the way and then put the case and prop screw between the vise jaws using scraps of thin plywood or clean sheet aluminium as pads to prevent marking. Line it up so it's all in line and then push the crank out the back of the drive washer.

I re-install same as you do.

Some of the engines do not have much fore and aft play. For those it's going to be much harder to install a thrust washer. For the rest there's often a good 10 or 15 thou of play. You can test if the metal will fit by pulling the drive washer forward and inserting the chosen shim material. If you can slide it into the gap and there's still a degree of fore n' aft movement that you can feel then it's OK. I'd suggest something like 4 to 5 thou shim material. Even 3 thou would probably be fine. Any thinner and you risk the metal crumpling if something gets caught in there.

For the engines that are tight enough that you can't get the 5 thou shim in there and still have about 5 to 8 thou of play then you gotta get more serious.

A lathe would be the ideal solution to trim the case down by a few thou.

In a pinch you could use a drill press and a dremel end cutting burr to trim the case. In this method use the depth stop to ensure all the plunges are the same and take off only a very small little nibble at a time and then move the case about 1/32and take out another nibble to prevent the end burr grabbing and pulling it out of square. Just reduce the whole end by about the thickness of a couple of pieces of writing paper. That's about 6 thou the last time I checked.

You can even do it with a hand file. Pad and grab the case firmly but carefullly in a vise and take of a couple of strokes off the end with a fine tooth file. It would help if you put a scratch mark about 5 thou down on the outside and file down to that line. Use the crankshaft inserted from behind to check the progress for distance and rough squareness. Don't go too far and try to keep the cut end as square as possible. Now mark the filed end with a felt pen and push the crackshaft in from the nose end and turn it around a few times to scuff off the ink from the high spot(s) and remove. With a careful touch just file a one inch stroke off the shiny bits. Now re-ink and re scuff with the crank. Keep doing this until the high spots are cut down and you have an even scuff line over a good portion of the end face. Deburr lightly with the file on the outside and an xacto knife on the inside as you go to allow the crank to go in easily. As a final step I suggest a bit of 400 grit wet or dry with a hole punched in it and placed over the crank and use that to polish the end face a little and level out the worst of the remaining high points. Now wash it all up well with some hot and soapy water, dry, oil and assemble. The whole thing will take you about 20 to 30 minutes. Work slow and attentively and try to feel the seating of the file. It's fussy work but with the ink and some reasonable care similar to what you use already for general model building it's very doable. The key is to use the inking and scuffing to sneak up on the whole fit in very small steps. Especially when you start getting lots of shining points from the scuffing as that means you're REALLLY close to a great fit.