have you given any thought to how you're going to tote the completed piece around?
Just from hefting the pieces around; the barrel has got to weigh a bit under 200 pounds,
and the sled feels like it is at least 250.
I've got a young buck for a neighbor- he helps me move the pieces, or if he's not around,
I have to use a 'take apart' style of engine crane.
The 8 clamping bolts on the sides are really just for show.
I've scrounged some nice 1/4" plywood from a packing crate to cover the mid-section plates with.
The lower four corner thru-bolts will have the original style extensions, more or less to scale.
They're to short for wheels to attach,
but they'll make perfect lifting points for a sling made out of old cargo tie down straps.
To transport it:
I figure the mortar and the (disassembled) engine crane both will fit in the back of my F-250.
That'll work until I get a small tiltable trailer built for the crane & mortar to fit on together.
Getting the main piece of the crane in/out & put together is do-able, just sort of a hassle.
Another option:
I'm the fabricator, painter, and welder for a high security safe & vault company.
I can borrow specialty safe moving trailers, lifting equip., and pallet jacks from the shop.