If the 2 compensation tubes are bending it would mean there is not enough packing gasket under the emulsion tube Mystyler ,I had a look at a carby of mine and it has 2 red fibre washers under the emulsion tube where the image above looks like it has one fibre washer but if two fibre washers are too much I would use one fibre washer and make the other out of gasket paper.
The needle and seat you have is the same as one Pope carby I have the other Pope carby of mine has a tiny ball bearing to close off the seat.
If the needle and seat still leak after it's all back together ,you can try repairing them,the needle could be put in a drill and spun while some fine wet and dry sand paper cleans the needle point.
