Its made of 3/4" Baltic birch, including the back - no 5/8" stuff.
The covering that Mesa used here is really odd, IMO. It is very thick, and it is basically an adhesive backed vinyl. In other words there is no contact cement used, just a peel and apply process. I never knew this. To the plus side of this material, it has a dampening affect on the cabinet wood. The negative side of this material is that it has a dampening affect on the cabinet wood.
It looks like Mesa has moved onto another type of covering, more 'elephant skin' textured, but mine is smooth.My half back is 3/4" fir plywood and it is quite lively compared to the main cabinet wood.
Anyway, this cab sounds really really good. I bought it used with a swapped out original G-12 65 in it (it came with a V30 from the factory) and have now swapped that for a Weber 50 watt alnico Silver Bell. The Silver Bell is much warmer with less bass than the Celestion. I may revisit the Celestion but for now, the Weber rules this cab.
Has anybody else tried this cab?