I'd agree with DonC. Since you added the info your
oil pressure gauge stop working, perhaps thats because you have no
oil pressure. If you havent figured out the root cause yet, a few pics of how you have your system plumbed would help us. perhaps (remote adapter??) the filter was mounted to spewed the parts. You've eliminated the filter at least, but the components you found are definitely a by-pass or check valve. perhaps you're using a remote mount system and its adpater has lost its valve
. In any case, it goes without saying not to start that motor until you can confirm you have
oil pressure using a hand held mech, test gauge while CRANKING engine with fuel/spark disabled. good luck. If it was the remote adapter, please share the brand and part number so other folks here can be aware.