Saving Old Seagulls

http://www.liquideng.com.au/corrodip.html
Many e chemicals company have (with different commercial names) similar product.
Personally I run seagulls in a tank filled with descaling fluid for household heating systems and then flush them in a fresh water tank, it solves almost all water cyrculation ...

Of corse I am speaking of RADIAL freeplay, as axial (vertical) play is perfecly normal and necessary, according to official workshop manual

Anyboady could tell me the correct maximum "official" freeplay between upper and lower crankshaft ends and their bushings?
I rebuild many Seagull and other vintage outboard in my spare time, and I noticed that almost systematically ALL Seagul thast show to have been used a lot got a remarkable (up ...