Glad to see you sorted this
If it is an old carb that has just let the petrol evaporate, Sticky’s book has a good tip which I have only just read. The brass housing for the float needle needs polishing as it gets encrusted with muck making the needle stick. Do this with an ear bud dipped in chrome polish and attach that to the end of drill. I have done one this week.
It won’t necessarily resolve all issues as, if there is muck in that housing, it stands to reason that there may well be encrusted muck in the internal passages. They may, if you’re lucky, be cleared with ultrasonic cleaning.