Cryselco 1960's 80w fluorescent fitting

Here's quite an interesting old fitting I saved this morning from being disposed of - it dates back to the 1960's (so older than most of my other fluorescent fittings!) and is of quite an unusual design, given the lampholders are attached to the fitting's cover as opposed to its spine. From the fitting's side profile, it obviously seems to be a bit of a copy of the Atlas Superslim - perhaps it was just taking advantage of its popularity at the time! This had probably been in someone's garage for years...