If the shaft has really eaten out the tunnel where the bearing is knocked in the only way I could suggest to block the oil gallery is to drill, tap and plug it up permanently. Other option is a one shot deal - weld it up (I'm not hot on suggesting that either) I'm not 100% sure of what the access is like to those oil galleries and if those ideas are feasible. And the spring? Is it out of the oil pressure regulator in the oil pump? To me it looks like it's too wider diameter for the fuel pump rocker arm and I'm not sure how a jet valve spring could've make it to the sump (I'd be more than happy to be proven wrong on that one). Funnily enough I found chunks of similar looking spring in my sump when I did an autopsy on my 4G63 - it suffered a catastrophic internal failure that pretty well wrecked most of the engines' internals. To be honest I think you're gonna have to pull the engine out and investigate further...