Yep, those are les davis cutplugs. They stopped producing them in the early '90's.
You can run them naked or if behind a flasher you want to be at least 7' back. They have a super tight , fast spin, so the slower you go the more effective they can be.
Last August we ran out of bait fishing out of Ucluelet and I ran a 5" version with no flasher and had plenty of salmon action plus a couple halibut when I ran it close to bottom.
Personally, I'd much rather run real bait (herring or chovies) than a fake plastic cutplug.
If you're gonna run plugs then buy a few tomics, at least then you know you're using something that is well proven.....No flasher and about 40' behind the release or longer if you are not around a lot of other boats with gear in the water.