mismatched heads......

Hello to all.......friend restored a 41U recently...the motor had these alloy heads on it......
any ideas what the left head is.....the right looks oem,has the 2 compression indicator lines etc......
the left has them too...but short......
left looks very different......no idea how this motor was running ever....if it was......
could this be an older after market head......
the oem ones fins are trashed....the other is very good......would be nice to find a set for this........
any ideas would be appreciated...thank you

heres the foto......

The head on the right with the 4 in combustion chamber looks to Me to be a cast copy of an IRON head!
Two thoughts, Some one or some company copied an Iron head.
Or this is a 1936 alloy head for the VLH model- they had shorter fins and were shaped like the Iron head.
The one on the left looks like the factory alloy head for UH, ULH.
The relieving done to the OEM style Left head with the 7 mark.
Maybe this was clearanced to accept Military JEEP pistons!
Did these come from Europe or South Africa?
I have an inkling some joe in a motor pool made these work with what they had on hand
don

2 more.....any ideas....very different in shape...