I use a heavy oil in the crankcase ie 60W. Only use steam oil for the cylinders, it is not a lubricant in the same sense as regular oil. It is designed to , for lack of a better word vaporize, in the steam to provide lubricant to the cylinder. I will never forget my first time out with my live steam locomotive in the early 80's getting admonished by the old timers for putting steam oil on everything.
That engine was used for speed boats, but I have never seen a picture of one. It was also used to power a generator. During WWII there was a kit that had a boiler, the SIRIUS, and a generator all in a box. You put the boiler over a fire. It was used to power radio equipment I believe. The color of your engine makes me think it might have been from one of those kits. I looked for my picture of a kit but could not find it but here is a link
http://www.mapleleafup.net/forums/showthread.php?t=22842.
Bob
[ Guests cannot view attachments ]