Refurbishing 1973 Large Advent speaker

I am refurbishing a pair of large Advent speakers from 1973. The tweeters and cross overs work, but the woofers are garbage replacements. My question is... Is it better to buy a 2nd hand 1975 original woofers and roll the dice on them or buy a pair of new replacements from simply speakers? Say they are the same price... is there enough magic in the originals to warrant the risk?
I would upgrade the caps and get a new pair of drivers. The DIY audio forum will have all the info youll need. 
Generally, these speakers are only worth a little bit of work.

If they get at all expensive, it will be much better to start a brand new DIY kit from scratch.

One thing particularly difficult for noobs is finding a woofer that matches the cabinet, and then adjusting the crossover for it. It's a lot lot harder than you think it is and not really worth it. It's like the tail wagging the dog kind of situation.

I replaced the woofers in my pair of the Small Advents with woofers taken from a pair of KLH's (rubber surrounds) that I bought cheap from GoodWill. Worked perfectly fine! So you could do the same! A beat-up pair of AR's or KLH's can yield a nice replacement pair of woofers - with no change in SQ!
Rubber surrounds are certainly. preferable to foam (ugh!).

Rubber surrounds are certainly. preferable to foam"

Some rubber surrounds are of poor construction, materials quality, and fabrication and some are not and the same is true of foam.