Make that "2 odd ducks"
From this source (which is Arizona Models and so now I am LOL
) it appears that both the Benz 100 and the Benz 150 had offset cylinders! Check out the diagrams.
http://www.finemodelworks.com/arizon...Benz/Benz.html
These diagrams are however what I call drafted "sketches" because they contain both errors and simplifications! You must check and recheck against photos if you use them. You can see the Benz BzIV sketch for my engine and I believe the sketch reference for your BZ III engine. They provide a good starting point but for my purposes a much more detailed engine plan was needed. Luckily I found one. So if this is "all there is" for engine documentation then you go with what the diagrams are telling you - now their are two engines with offset cylinders. And in the fast & quick evolution of engine design the offset cylinders were abandoned for the design of the BzIV.
I was trying to help, didn't really mean to do this to you... Maybe email the museum curator and have them take a photo straight on for you to analyse.
What to do eh!
You've uncovered quite a mystery here Don. If offset cylinders are for real then you have quite a unique engine to model. If the offset is erroneous then you still have a nifty engine to model...
Are you still enjoying this?
Cheers,
Brian