I'm lucky enough to have acquired one of these from a friend

Its a .177 carbine version, in rather lovely original condition.
So I have some questions for those who may know something about these rifles

Is it easy to date these? Mine is a tap loader, but has the raised maxi grip rail, and the williams type adjustable rear sight, and an adjustable foresight. From what I've read, these models were made up to the early 90's

What sort of muzzle energy should these make, in good mechanical order?

Has anyone successfully fitted scope mounts, that give reasonable cheek weld and eye relief, or are they best left with the fitted opens (which offer great cheek weld)?

Thanks in advance
Rob