Check the number stamped in the base of the carby body. You will need this to order in the required carby kit.
I knew the top gasket in the carby was broken up, and the car wasn't running very well so I decided to put a carby kit through the carby while it was off, and check it out.
Before you remove the carby start the engine and let it idle, pull the wire off the idle cut off valve(anti diesel valve) if you don't know what this is it's the only electrical connection to the carby. The motor should stop. If it doesn't your idle cut off valve isn't working, even if it's clicking. You'll probably find your car wasn't idling very well, and running rich.
First remove the carby from the car, remove the four nuts at the base of the carby, undo the choke cable, pop the throttle linkage off, and remove the 4 nuts the hold the air cover on the top. Note the way the various anti pollution pipes were hooked up, and label them with masking tape if you don't trust you memory.
Buy some carby cleaner and using a tooth brush give the outside of the carby a good clean, most of the red staining will spray straight off.
My carby after I pulled it off. Note how dirty it is especially
around the accelerator
spindles, they will need checking.
My carby once stripped. I only have a very cheap digital camera, so the quality of the photo's isn't to flash.

1. The broken
up old top Gasket
2. The
Jets
3. The
Screws
4. Carby
Body
5. I
really don't know
6. Carby
top
7. Left
side of primary spindle mechanism
8. Fuel
Filter
9. Float
and needle/seat
10. 1st
part of the right side of the throttle spindle mechanism
11. 2nd
part of the right side of the throttle spindle mechanism
12. Choke
cable clamp
13. Choke
mechanism
14. primary choke butterfly
15. Idle
cutoff / anti diesel valve
16. Hi
idle diaphragm
17. Accelerator
pump diaphragm