First, check out the listings for the AMERICAN ARMS guns listed on this site....your Tristar was also sold under this brand name...AND an important piece of info is also needed...Ejectors nd their springs are GAUGE specific..in a nutshell..what works for a 20 ga will not service a 12 ga etc. but the parts in question can be hand made fairly easily...The Ejectors are basically, a piece of round steel dowel with a flat attached to one end..the dowel and the flat are then shaped to a specific fit..As to a coil spring..any that fit the hole and supply the power will do...it doesn't matter what they started life as..a spring is a spring is a spring..it is the application that makes different...to that end...you can buy 10" lengths of different wire dia coil springs from
www.brownells.com. Back to TRISTAR... there may be other "brands" that were imported and sold..the exact same gun with only a different tradename...knowing what these are(if any) will help in finding someone parting out a gun on-line