I would give it a shot Marc, the LOPT and dropper are very good quality items that never seem to fail. Most of the problems were with the RF deck and the horrible slider presets, and of course the Emiscope CRT's going flat.
The Z77 valves were also notorious for shorts, but can be replaced with EF91's
It would be worth checking out the following items that were faulty on my set.
The frame output tx had an open primary.
Chokes (L17, L18) were also open, as was the 2.2 meg resistor on the RF deck.
All the presets apart from the width pot were open.
I would definitely recommend removing the RF deck, it is so much easier to work on with it out of the main chassis.
Having proved that the valves are ok and CRT is reasonable in my HMV set, I will have a go at getting it working.
You may be lucky with yours, not all the CRT's will be as flat as mine!
The biggest headache on mine was finding the fault on the RF deck.
I will hopefully finish of the remaining jobs on the set today, fit the back and call it done. I will keep a look out for a basket case set to harvest the CRT and chassis. this set really does deserve a better tube.
Mark