Loudspeaker repair: Tweeter problems, damaged crossover?

I would greatly appreciate any advice on repairing my lovely vintage Mission 752 Loudspeakers on ebay. I bought a 2nd hand amp to drive them but after a few days it died. I then bought a new amp which started to switch itself off intermittently when driving them. so bought a multi-meter to hopefully find the problem before any further damage. Initially I thought the tweeters were blown as this model has a reputation for easily damaged tweeters if stored in damp conditions etc: These were in storage 5+ years before I bought them... However after testing I think it could be the HF crossover components (possibly?)

Speaker Specs:
4 BiWire connnecting posts: HF/LF
General resistance: 8 ohms
Tweeter resistance: 4 ohms

Here are some test results:

Low frequency binding posts: approx 7 ohms
High frequency binding posts: infinite ohms
Direct tweeter coil reading: approx 4 ohms

Does anyone have an idea what could be the problem? I'd ideally like to repair them but don't want to sink more limited funds into them without an expert opinion.(

I've seen original replacement crossovers on ebay for 30GBP (+shipping)

Many thanks!