I'm pretty sure the lights that could use that bracket on the forks were discontinued around 1984, but I suppose that wouldn't necessarily stop Elswick using them.
You should be able to find date codes on some of the components to give you a fair idea of the year.
It appears that by the end of 1984 the Elswick brand had disappeared, and they sold bikes under the Falcon brand, so this means this is pre 1984 I guess.
I would have thought the late 70's or early 80's with the suicide brakes - I don't really recall seeing them by the mid 80's. Rear mech looks from that era too. The crank looks like it might be a later replacement.
