Are your new barrels going to have LH twist Enfield pattern rifling?
If the fit of the new barrels are all over the place due to variations in the action threads I suspect that the complaints from the purists will be enough to shut down production of the new barrels. From what I have read armorers are using to installing standard replacement barrels or tossing receivers that do not work.
You should be lining up real gunsmiths who are used to fitting barrels and clocking them. Don't flame me I am just stating the obvious.