Interesting. I've seen the Megatron site but for some reason I never really looked at it.
"Our experienced exposure meter specialists also recommend a wide range of repairs and servicing to all Weston Master & Euromaster exposure meters: Calibration check - £22; Recalibration, servicing and minor adjustments - £36; New photocell fitted, recalibration & servicing - £42; New movement fitted, recalibration & servicing - £55; New photocell & new movement fitted, recalibration & servicing - £66. All prices include UK carriage and VAT."
That's a lot of money, especially at current exchange rates. But if you love that Weston Master, that might be worthwhile.