[Arran]

Ed;
One thing that I will say about these is that Brand Z was considerate enough to make these mica caps easily accessible by undoing a machine nut, unlike the Automatic style ones where you need to drill out a brass eyelet, and take most of the IF transformer apart to get at the caps. The latter was considered disposable, if something went wrong the intent was that they be replaced, which would not have been an issue up until the early 1970s maybe, but not 50 years on from that. Then there are the ones who think some components are eternal parts, like the filter caps in an RCA Radiola 17 or 18, or molded mica caps, I have encountered bad ones in both cases, most mica caps are fine, but some of the post war Aerovox mica caps are often bad, the light brown ones, and it seems to be an issue with age, not with voltage given the circuits they were in.
Regards
Arran