JBL L55 Repair Questions

[Fugacity]

I am new to this forum so my apologies up front if I make any social blunders.
I acquired a pair of JBL L55s that I am restoring. I have some questions:

1) My speakers have metal glides on the bottom. Were these factory supplied or did someone add them? (photo attached)

2) One crossover board has a large black burn area (photo attached). Is it possible for a crossover to overheat or is this burn mark likely the result of carelessness from someone working on the board?

3) The tweeters aren't original (brand unknown) and I would like to find LE20-1 tweeters. Are these tweeters any good or should I look for something better? I prefer original where practical but if the sound is bad then upgrade. Also, does anyone have a photo or specs of the original tweeter mounting screws in regards to size and appearance?

Thanks

[grumpy]

looks like someone smoked, then replaced the power resistors (white rectangular bits).

I'd look for original tweeters... There are "better" tweeters, but then they're no longer L55s
and you'd have to deal with a different response, crossover (maybe), sensitivity matching, ...
and a loss of resale value, if that's a consideration.