Looks real nice. How did you join the side rails to the front
and back frame?

Thanks.

I used mortise and loose tenon joinery through the entire carcass. I became
a big fan of this type of joinery after getting frustrated with traditional
tenons. My shoulders would sometimes not lining up all the way around the
stock using traditional tenons. After watching David Marks on TV (almost
always uses loose M&T's) I started to use loose M&T's.

The plywood sides sit in a rabbet that are held in place with metal
fasteners.