Thanks for the useful information.  I'm in the process of putting the engine back together and I don't see how I can press the bearing out of the main bearing housing?  Are there any special tools or techniques to get this done??

Thanks for the comments.  I had some crocus cloth and I went ahead and lightly cleaned up the crank journal.  There was no roughness, but with a bit of careful effort, I was able to remove much of the discoloration from the bearing journal.  While at my local NAPA store, I rediscovered plastigage.  I checked the clearance and it's between .0055" and .006".  The maximum spec is .0055, but I think I'll go ahead with the rebuild (any concerns?).  Good comment re the oil pump.  I took it apart and found one of the o-rings was broken, but the clearances appeared good ok so I purchased the two required  o-rings along with a gasket kit for the engine.  I've also lapped in the valves as there was evidence of leakage.

As I've never been around one of these engines, and I'm replacing the piston and cylinder. I am looking for any break-in information as well as starting and operating information.  This unit has an electric starter so it should be easy to get it going.

Thanks for your comments
One last question, what is the oil reservoir and plunger that is screwed into the intake manifold?

Thanks very much.  Looks like he has everything

I'm rebuilding a Lister ST1 and need general specs such as torques, clearances, etc.  I would also like to obtain a parts book