Vintage Cars: SU carb damper, cheap source, odd problem

Question
I bought a 76 MG midget last year. It runs fair after warming up. Upon inspecting the damper I found an odd problem. The brass tip of the damper should slide snug into a sleeve. But the sleeve that this dampers slides into is way to big. I don't know if there is a larger damper to fit into this orifice or if there is a replacement orifice to fit the damper I have. There is no way I could put and keep the oil in. Other than replacing this whole carb. Thanks for any advice.

Answer
pretty sure there are a few sizes of damper, i'd guess the original owner lost the screw/damper insert and fitted this without checking or caring about the size.

Get me the numbers off the carb and I'll find you the numbers for the right part (and probably a cheap source) ;)