Gearbox Gaiter

Hello
I am looking for a rubber gaiter to fit the manual gearbox on a Alvis TF21. The gearbox is a ZF S5-20.
Basically it’s the rubber boot that’s attached to the gearbox and around the gear stick.
The diameter of the hole on the gaiter where it attaches to the gearbox is 36mm.
The original part was Lockheed,  437  J(E)143, these are the numbers cast into the existing rubber gaiter.
Any thoughts of an alternative gaiter will be appreciated.
Brian

Hello Again,
Unfortunately there was no response to my query. After having tried all the obvious outlets, including specialists  who deal in other makes of cars from the same period where the ZF gearboxes were fitted but they were unable to help either. However, necessity became the mother of invention and hopefully it’s now all sorted but only time will tell.
Brian