What I'd do is remove the woofer and midrange (they should simply unscrew and then lift out) from the cabinets, and get the numbers off the magnets, then search eBay for those numbers and the word
Pioneer. Pioneer would have used the same components in several different speaker systems, so searching on the speaker's model number is rarely helpful. Take care not to break the wires when you pull them out, and make a note of which wire attaches to which terminal.
Keep in mind that these aren't top-line speakers (they originally came as part of a rack system, which you may still have). Depending on what the used audio market is like on Craigslist in your area, your efforts might be better spent in getting your husband a replacement pair of speakers instead. If you find some ads that look promising, people on Audiokarma are always willing to give their opinions on speaker purchases.
I found this picture online; they're fairly typical Pioneer three-way rack speakers.