Don't know if anyone is looking for used pump action parts kits (most calibers available) but the folks over at Everygunparts have listed 69 different offerings today. That's the most I've seen in a longtime. Plus they are offering a 10% off to new customers. No affiliation other then a prior customer.
Pump Action Shotgun Parts Kits
Shop for pump action shotgun parts kits online at EveryGunPart.com.
everygunpart.com