Solex carb on 1975 114 (280)

I found the seat for the float needle valve loose in the base of carb causing the car to flood out at low rpm and run rich at other speeds. I don't see anything that would hold the seat in the base other than a press fit. Now the seat just drops in the bore with a loose slip fit. The carb was recently rebuilt before I got the car according to maintenance records. The needle top also appears to be filed off. Looks like someone really butchered these parts. Any info on how the seat is supposed to be secured will be appreciated.