Does anyone know of a half decent silncer that will fit on the end of a Air Arms Pro-Sport?

I picked a second hand one up cheap at a car boot sale and unfortunately for such a lovely gun it been a bit neglected. One problem is the internal baffles have been shot away. I've got most of the remenants out but there is too much stuck inside to replace the baffles as they would no longer fit inside the shroud.

So, I want to put one on the outside. Are there any that would fit?

Cheers.