Ancient Ohms

Recently, I opened up a couple of cabinets i obtained years ago.

The woofer is an AK 121 and the horn is a GP1, 550Hz 3-cell horn. The cabinets were marketed in Canada as Vitavox Bitone 3200 speaker units. The drivers themselves are in excellent condition and sound like that as well. I believe each driver is 15 ohm. What should I be concerned about when trying to buy a small amp for these? I’m using a sub-standard, solid-state receiver amp right now but wonder if a tube amp might be more appropriate?

Any thoughts?
Those were mostly used for commercial installation(ie: movie theaters). They’re pretty efficient, so- don’t need much power, as you’ve undoubtedly noticed. As far as amps and, "appropriate": that only depends on your tastes. Given their rep for being rather tipped-up in presentation, you may prefer the sonics of an older(unmodified), warmer-colored, tube amp or receiver(Fisher/Scott/Dynaco/Eico/Marantz/McIntosh). Just depends on your perceptions/dedication/finances.
I was more concerned with the 15 ohm speakers.  What limitations should I look for in a small amp with them.  I don't want to mismatch them or cause damage.
As long as their surrounds aren't torn, you could probably hurt your ears first, with anything over 35 WPC, unless you have a rather large room and enjoy high SPLs.  Virtually any vintage tube amp, will have 16 Ohm taps and as easy time driving them.    Relax and have fun.