There are a few engineering firms around Weymouth and Portland but whether they'd be prepared to carry out a small, one-off task for a private customer is another matter. Most seem geared up for producing parts for the defence, aerospace and automotive trades, and similar high-grade, high-value work.
If they did you'd probably think you are buying a new pressure-washer, given that ordinary trade-rates are in many tens of ££/hour.
I take it a manufacturer's spare is unavailable.
PM some details and I'll see if I can manage it.
Shame about having to leave your lathe behind. Obviously at the moment nothing's going anywhere soon, but no chance of finding a machinery-removals firm to recover it for you?