The long version:
I've been messin' with LBC's since 1969, first my own, then for friends and later for clients and money. If there wasn't a BMC/Leyland dealer around locally, the source for SU or Stromberg carbs was Joe Curto. For the last couple decades we realized it was more cost effective to just ship the carbs to Joe's for refurb rather than to fuss with taking them apart, ordering parts (from guess where), reaming bodies for shaft sleeves... yadda-yadda.
Grantura_MK1 is silly enuff to still be in the business, :wink: but his advice is both sound and correct. The restoration shop a pal and partner of mine had in Sarasota for decades has now officially been shut down for about five years, but that's still a couple lifetimes of experience to endorse Curto.