Boys, you can't just swap speaker drivers will nilly just because they may fit. Well, actually you can, but the speakers won't sound the same or as the designer intended. The xovers were designed for a specific dynamic woofer driver. Substituting a different unit will almost certainly work (in the broadest sense of the word) but it won't be optimal. Unless you are talking about vintage Tannoy or Altec drivers, exact replacements are usually not expensive, especially used. And substituting non-original parts is going to make your restored speakers hard to sell and/or lower the value for resale.
Snell Type A
I found a pair of Snell type A speakers at an estate sale the owners agreed to $250 for the pair. They say the speakers work. They look in decent shape. Is that a good price assuming they are working and a follow up question. I see they show a 4 Ohm input; will my mid-level Denon AVR-X3300W power them?