1957 Napco GMC- junkyard rear end?

[Yewhi]

Trying to decide where to go with this. Below is the current rear end. Ignoring the rather spectacular red neck engineering, do you think that this is original?







It appears to be either a Dana 44 or spicer 45 which would've been correct but the backing plates appear to be wrong. I highly doubt this is original but would appreciate input as I don't know a ton about GMC trucks from this era.

If it isn't original or correct than my question is what next? My first impulse is to junk it rather than deal with undoing the 40 year old welding mess that comes with using it. I managed to pick up a chevy 10 bolt rear end for 125.00 that's in decent shape and would be a good option if I don't care too much about originality.



The only issue is the Dana/Spicer is geared 3.54:1 (based on the tag on the differential). I have not been able to locate 3.54 gears for the ten bolt. Assuming the Napco front is also geared 3.54:1 this could be an issue. So my second question is, does anyone make 3.54 gears for a ten bolt and if so where can I get them?

Thanks in advance!