Assistance needed to identify this engine. Make/model/year. Thanks.
Absolutely no clue as to answers for your make/model/year questions, but I must say that co-axial (or is it co-linear) compound is quite amazing!
In the first photo, there is part of a brass plate visible that clearly has some words engraved on it, but about half of it is not visible. What does it say? But absolutely I agree that this would appear to be a very unusual and interesting engine!
Nice model of a tandem compound.
Gil
The plate is just a generic one that I added using the description the seller used.