Brake Booster failure

[BobPhx (Bob Brackney - 89 XJS V12, 5 sp/Marelli | 2013 XKR)]

Hello-
All the details are here:

Teves III convert back to vacuum booster - questions

As part of my ongoing 5-speed conversion, I am thinking I want to toss the Teves III over the hedge and go back to the 88-earlier vacuum booster / master cylinder set up. The III is not really rebuildable, probably dangerous due to age or design, and I need an accumulator ball which is $300. And I don’t really care about anti-lock, so I am not interested in going to the cost/hassle of converting to Teves IV. I have a Teves III pedal box with a clutch pedal, so I’ll fab an adapter plate that w…