Hi, I too am having fueling problems, more of that later. I have a saved search on ebay which has returned the following:
https://www.ebay.co.uk/itm/JAGUAR-2-SU-HD8-CARBURETOR-PARTS-E-TYPE-MK10-ETC/282767466155?hash=item41d6411eab:g:1twAAOSwovNaLWck
https://www.ebay.co.uk/itm/382307843339?ul_noapp=true
No idea if these have the part)s) you're looking for.
My Problem(s), maybe you can help.
1966 4.2 ltr MK10 3 HD8 carbs.
1 - I can't get the tick over to sit at 600rpm. It seems to work but when I start it the next day it will only ide at about 250rpm
2 - I've fitted new needles but, using colourtune, I can't get a decent blue flame no matter how weak I make the mixture. Lifting the piston with the lifting pin indicates the mixture is correct.
3 - Carb 1, with the auxilary starting carb, backfires occasionally and blows petrol back through the auxillary carb.
4 - I have a small oil leak at the front crank oil seal, do you know if this is easy to change or do I have to remove the sump?
Hope you can help and hope I helped you.
Neil.