[BrendaAnnD]

If you are getting high ohms across the plate coil, the coil is open. These coils are typically pretty easy to remove for further inspection, or even rewinding.

If it is only the primary (plate) coil that is open on this coil, it's extremely easy to rewind, as it's only a relatively few turns over the secondary, and is not super critical as it is not a tuned circuit. Of course, the closer to the original, the better the performance will be.

There are also folks who do professional rewinds, like Neil Sutcliffe.