A lot of TD mods come from the days when used engines and parts were plentiful and cheap !
Folk would mod and tune and the engines would scream , and maybe last 5 to 10 runs before something wore out or broke ..
Then they simply built a new engine , it was not uncommon to see TD fans with tool boxes full of parts , maybe enough parts to build several [ dozen ] engines . I remember one boast , where a writer boasted enough parts to build 50 engines .
Yes , some folks were serious about there TD's
These days , Id say you would most likely like to see more than 5 to 10 runs from an engine
A lot of the old time [ 70's - 80's mods ] are really not that suited to today's cost VS availability ..
By all means chrome the case where the shaft runs .. Dont over polish the chrome as the chrome is really ?? porous - lumpy - what ever , but great for minimizing surface area , offering a harder surface and better lubrication retention [ unpolished ]
If you have a good chromer , then they should be able to control the amount of chrome you lay down , a tenth of a thou should be plenty ..
If you have a few cranks of varying dia , to use , this would be best .
Find one thats just about right after chroming , and run it in with some 30% oil fuel , maybe 10 minutes , then another 10 minutes on 25% and then 10 minutes on 20% Dont lean out the engine , you want the shaft swimming in fuel [ lube ]
After this the high spots on the chrome should be gone or minimized ..
Now , check shaft fits again , and build the engine as you would a new one ..
Again everyone has there own way of doing things , and there are many right ways of building engines , the wrong way is when it does not work
And the way to learn to do things the right way , is to eliminate all the wrong ways of doing it ...