I have two L-134 engines, 
- one in my '51 that has a cracked cylinder (water must have go in and froze)
- second is one I bought, and supposedly ran, but has issues.  It came out of a salad DJ,  so who knows what its origins are.  (it has a Willys Industrial head on it).  I need to "rebuild" it.

I tried to ID using this webpage:
http://cj3apage.com/index/Tech_Tips/casting%20numbers.htm

Unfortunately neither of these engines has a serial number on the top, near water pump casting.  Is it common for these to be wiped out if the block is decked?

Any thoughts on any other ways to ID?

Block casting numbers
1) 641087-L-W4
2) 641087-L-W3

Do you mean photos of engines?  I can take some tomorrow.

Here are some photos of the serial no. areas. 
and a photo of my "wall art"  -> the two heads that came from these engines.  The Supersonic was on the engine in the '51,  the Industrial was on the replacement engine.

The 641087 casting number is one of the more common for the L-134.  Late 2A, 3A, replacements, welders, and I believe,  some Wagons, and some Jeepsters have this casting. I believe the "W" stands for Wilson Foundry. The 3 or 4 is the cast form number.

Because the serial number is gone it may be difficult to determine the original application for these engines, but you might be able to date it.  There might be a date stamp on the edge of the engine surface...where the oil pan mounts.

Tim