I thought you may have put some insulation under the cleading as you intend this to be a working engine
Certainly runs nicely, have you tried adding a bit of load – finger on the flywheel is an easy way to do it and the note from teh exhaust should change. May also be worth thinking about a couple of drain cocks to get rid of any condensate as you are going to be running on steam, think about a small oil cup on the eccentric too. You could also allow for an eccentric to drive a boiler feed pump or just fit a hand pump into teh plant and remember to use it
As your intended load is quite constant I doubt a governor will be needed.
Whats next a boiler?