Hi DerFly, I recently restored two of the .50's which are exactly the same as the .58 except for internal displacement.

The finned cylinder simply sits on the lower case on a paper gasket. It is not screwed in. It is the gasket that has "glued" the two parts together due to heat and castor oil. You will more than likely destroy the paper gasket when separating the two parts of the case. No big deal, I replaced mine with thin automotive gasket material.

Be very, very careful with the front bearing!!! It is most certainly a roller pin bearing of unusual dimensions: 13mm ID x 18mm OD. You will not be able to find a replacement from places like Boca or RC Bearings.

Here is my thread with photos of one of my restorations:

http://www.rcuniverse.com/forum/m_61...tm.htm#6166814

My .50's are fantastic runners. I have one in my Senior Falcon. I'm sure the .58 is only more powerful.

I have an extra prop drive if you need it. It, too, is an "oddball" part that is difficult to track down.

David