Can someone help me identify this old Shimano derailleur?

I can't find the exact model, but it looks very similar to this one that I found on VeloBase. If you have the patience check out this list. Shimano starts around page 8. I suspect it might be a bottom of the range version of a Light Action, but I'm far from an expert

EDIT:

I think it might be this one. You're fortunate I stumbled across this question when I was in the mood for a bit of a treasure hunt :)

My guess is that it's RD-L541. And it's paired with a 6-speed cassette, which is consistent.

EDIT: I should have clicked on the link posted above. Looks we arrived at the same conclusion. So, I'll just post a picture.