If you can't figure it out ask Nordic Tug, they'll likely have a record of what they used
NT said might be Cantalupi. One other person said the dolphin is a Southco logo. I am on the scent.
Looks like a great time to replace those lenses with polycarbonate. I'd hate to step on the broken glass.
If you are worried about the coarse thread "jars" unwinding themselves use a dab of something, even silicone(hush Mr. F)as a hold, which applying force will overcome.