They didn't use gold foil in the early days at IoW, that wasn't until the later '70s.
And they only had a tiny amount of the teal left over from Mdina which was all used up in the very early days. Before foil. So I'm afraid it can't be IoWSG. It has two completely incompatible features.
Snapped off/ broken pontil scars are found on attenuated bottles, which cover a number of years, and also on goblets.
Rather than being an indication of period, they really depend on what the piece is.
Some things are just easier to leave with the broken mark. Applying a blob of hot glass for the prunt can cause cracking problems on the thin bases of tall bottles and are not reasonable to apply to footed pieces.
I've just checked a couple of Ltd Edn pieces - an Undercliff Day baluster and a large North Sea rectangular vase - both of those have broken off pontil scars.
I don't know about candlesticks and lamp bases, but I imagine they might well have broken scars too.