Why a 155? They make a single spring 150 and a double spring 160. Just curious? Would the 155 be single spring or double?

I would ask Bill Duke to make these.

Duke already makes a 155. Built like a 110/120, just 5" jaws.

Not sure what OP has in mind, but compared to almost any other 160 I've seen (Duke, Victor and BMI), Belisle 160 is an absolute hammer. Perhaps is hoping for the same?

Regulations is the reason for the 155. Marten/Fisher trapping here in Maine the largest sized conibear we can use without an overly complicated cubby design is a 155. I think the 1/2” spread over a 120 makes a difference, especially on the bigger fisher. I know it’s still not the ideal trap, but working with the regulations it’s the best we got. I know many other states a 155 is also the largest conibear allowed set on land without major regulation. I ran Duke 155s on my marten and fisher line this fall, they left a lot to be desired. The 5” conibear needs a premium stout offering. The WCS 155 trap isn’t bad, but it’s severely undersprung.

I emailed with Marc this week, it will be a bit before this comes to fruition, but they do seem committed to making it work eventually. They need to make a new welding machine for the 5” size frames. It’s in the works but they need to do some other work first. He said likely won’t see them for this fall but the year after perhaps.

Still encourage everyone to email him and make the request. More demand will maybe speed up the process.