Don't have many non-US air guns but I do have a Greener. Picked it up about 15 years ago from a fellow in Vancouver, BC. It has what I think are the early markings of "The Greener Rifle" with London and Birmingham both listed. On the barrel where it meets the receiver is .177 and no. 124

Is 124 the serial number?

Gun is in like-new condition. Value today?