It is either a Continental or Hercules engine. If it's a Continental it is most likely an F162. The head on the Continental is truly flat with a bolt on elbow where the top radiator hose connects whereas the Hercules has a cast raised area on the head for the top radiator hose.
The Continental has a steel ID plate near the starter. If the plate is missing then there is no other ID. The Hercules model and serial number is stamped above the front timing cover typically starting with 3 or 4 letters.

Thanks for taking time to respond. I know it's old. Suspected 1960's. I only asked for model so if I came across maybe a wiring diagram or some type of operators/ service manual. I said 4000# capacity because located on the mast is a large sticker that says 4000# when looking forward from the seat. It does have the swing doors with oval cutouts. Giving this information what make of engine did Baker use? Let's say it's 1950's to early 60's. Did they use only one engine? It appears to be 12volt. Thanks

How do you know the capacity is 4000# if you can find a model or serial #?
If it has swinging doors with long oval cutouts to access the engine compartment then it is very old, probably late 50's or early 60's. If so, then the model/serial # won't make any difference because most of the parts are no longer available and haven't been for quite some time.

The rear tires are 6.00-9
Front tires are 7.00-12
How can I identify the brand of engine? It's a 4 cylinder propane is all I can tell. Also still cannot find the Serial Number anywhere.
Can you tell me how to upload photos or maybe offer your email and I can send you some photos.
Thanks for your help.

I provide the towing services my truck tire got damaged very rapidly what are the main reasons for it, how I can be prolonged my truck tires.

Depending on how old it is it should be stamped next to the floorboard or possibly above the frame cutout for the tilt cylinders.
What does it have for an engine and what are the tires sizes?