I suspect that may be doable. I believe Jim Chambers kits use Rice Barrels that are dovetailed for tenons & sights at Rice or via an intermediary.
Rice lists an Edward Marshall Profile barrel to fit
Chambers kits, and lists 40 as an available option (although not available in the drop down, may be a special order).
Dunlap woodcrafts also has an
Edward Marshall kit, and lists Rice as the barrel supplier.
I will be at Dunlap this weekend shopping for a stock blank, and at the Contemporary Longrifle Association show later this month. I'd be happy to make inquiries and pass along if you are genuinely interested.