I run rubber the entire length,, Used automotive flare fittings at the cooler and filter.. Installed Gates hose rated for oil and pressure.. been that was for 200K miles
My 1989 big block has the factory oil cooler hoses attaching to fittings on the filter assembly not directly into the block, but the correct lines are metal with a properly rated rubber section in the middle (hard lines all the way end to end would be prone to fatigue/breaking). The factory oil cooler lines on the British sports cars are the same way - metal fittings and short pipe on each end, rubber in the middle. So having rubber hose in the circuit isn't always wrong, but I'd want to see how these are attached - if its just a smooth metal end with the hose clamped on that could be bad. If those are the original metal parts there should be a barb at the end (and the remnants of a metal collar), where the original rubber hose would have been pushed on and then the crimping tool would have crushed the collar down similar to how hydraulic lines for heavy equipment are made (and those hoses take fantastically higher pressures than what our engine oil pumps could develop).
If there IS a barb on each end, good quality hose clamps would be OK if double clamped (similar to how below-waterline fittings on boats are done). I ran an MGB that way for years without problems when proper replacement parts were not (at the time) available. Those engines will build up to 80-90 PSI oil pressure, and the double clamp method worked just fine so I can't see why it wouldn't work on the 30-50 PSI we normally see on these Chevrolet engines (as long as there IS a barb present at the end of the metal part).
Based on how twisted that one end is, I'd still be inclined to replace because that metal has been stretched and stressed. Losing an oil line is never fun and certainly can get exciting (which is how I ended up with clamped on replacements with the MGB mentioned above).