Fingers is correct, as usual, it is a 36. For what it is worth, I am somewhat of a purist. I tend to prefer replicas that are close to the originals. For me, 44s are found in the horse pistols and the 1860. 36s are the 51s, 61s, and the Pocket series.
Anyway, here is another shot of the G.U.
It has some interesting features. I am fond of the rear sight notch in the hammer.
It does not have the safety pins on the cylinder so there is no cut in the hammer for them.
It is a four digit serial number but no date code is found. It is marked "Navy Arms Co." on the barrel and G.U. on the barrel lug but those are the only markings.
After shooting and gathering C&B revolves for nearly 50 years, it was the first 1851 I purchased for myself. It appears to be unfired and it will so remain.