OK, I'll start:

Jeffery .400 3-inch BLE, 24-inch barrels, 10 lbs even. Perfect!

Manton (John Wilkes) .470 BL non-ejector, 26-inch barrels, 11lbs 2 oz. A tad on the heavy side perhaps, but nice to shoot.

John Wilkes .375 NE (2 1/2-inch case) BL non-ejector, 26-inch barrels, 10 3/4 lbs. Way too heavy for the chambering!

Greener .577-65-650 BL non-ejector, 22-inch barrels, 10 1/2 lbs. About right, but could be up to 1/2-pound lighter.

And the oldies:
Alex Henry 20/.577 Express, ULH, 28-inch barrels, 11 lbs even.
Rodda (W&C Scott) .500 No.2 'Cordite Express', SL non-ejector, 28-inch barrels, 9 lbs 10 ozs.
Tolley .450 x 3 1/2 Express, TLH, 28-inch barrels, {Oops, forgot. Will re-weigh and edit later!}
Kavanagh 12-bore 3-dram Howdah Rifle, ULH, 22-inch barrels, 8 lbs.