To tame the recoil on the beast, you can get 2 7/8" 10ga loads from RST but just in smaller lead shot sizes. I'ds save the 10ga double for turkeys. While not a fan of the 10ga I did get to use a very fine old Remington hammer Sxs 10ga on a grouse hunt in northern WI, it was long enough ago that the Pickerel Lake store had paper cased 2 7/8" Rem 6's on the shelf. I've also shot some trap with a fine old Baker 10ga, again 2 7/8". I believe the standard load in the 2 7/8" was 1 1/4 oz. RST loads 1 1/8, 1 1/4 oz of lead and 1 3/8 oz of Bismuth..
If I'm not mistaken the Zabala is heavy beast approaching 10 lbs, The 10's I'm talking about were in the 7+ lb range.
If this is a inheritance from a beloved person and you cherish the shotgun you might just think about making it a wall hanger or turkey gun as it's days have past. It was designed to shoot heavy charges of Lead shot at waterfowl and that doesn't happen any longer.
If the chokes on it aren't too tight, no more than MOD I'd try some Steel BBB and not try and stretch it too far. Then again you could just reload for it and load NP "T" or "F"lead shot, if you just shoot new hulls you can get away with just a reloading manual(you can get a 10ga specific one) scale and Roll crimping head for you drill, no need to buy a 10ga reloading press. plus appropriate powder, wads and shot, new hulls come primed.
10ga heavy loads of smaller lead shot for turkey hunting are still available.