Where can I find meta-alloys without taking a risky fight?

I’ve re-installed Elite and after logging in, halfway to Saggitarius I decided to head back and check out the new content.

This lead me to the Engineers and I need one meta-alloy to get this storyline/ questline going.

Now according to various forums posts and spreadsheets, there should be enough to farm around. My problem is, that after a dozen or so locations I’ve checked with my cobra MK III, everything is empty.

Merope 5C is one of those unguarded spots, but most of the others are guarded by some mean looking imperial ships. I managed to sneak around some of them (they are after all a good indicator, that I’m in the right region) just to find some empty barnacles again. I’d rather avoid getting in a fight with them. I’m pretty sure my Cobra is not up to the task with its puny little lasers.

So how do I go about at least getting 1(!) meta-alloy to continue on. Is the respawn timer known for those things? Is there one? I’ve been switching between private and public every so often. I even jumped into hyperspace and landed again. Nothing did help.

Update
Although, this doesn’t answer the question, I finally found one at Pleiades sector IH-V C2-16 D 2 Lat: -1.7955 Lon: 141.2449. This one was watched by 3 small drones, which my board weapons took care of. Well worth the 2.5k bounty.