I believe you are correct in that he either started, or finished, his apprenticeship in Virginia. But - (and I hope I have this right - if not, someone else correct me) - I believe as a teenager Simon Lauck is known to have marched north on the ill-fated Quebec campaign and there is some documentation, or at least strong evidence, that either made his way back (or stopped) in Pennsylvania, and ended up working in Beck's shop for about 2 (?) years, before returning to Virginia.
Anyway, there is a fine signed Simon lauck rifle that looks to be about the earliest known piece surviving by him - looks 1780-85 ish, with a Lancaster daisy patchbox and the rest of the gun is basically a JP Beck gun - mounts, architecture, etc. It is shown in one of Whisker's books.The carving is nice but very simple, perhaps reflecting his youth and inexperience at the time.
As for the carving, one of the most common features he used was the back to back C scrolls with the small "petal" like leaves around the forward edge. This became pretty ubiquitous throughout the Valley and was carried into nearby areas, and also occasionally crops up on Lancaster PA pieces - the Peter Brong Rifle shown in Kaufmann is a variation. Lauck's architecture and mounts - particulary sideplates - are similar to some Lancaster guns from the same period.
When you look at Valley guns from the late 1700s you see a lot of similarities to Lancaster and York work - the Valley was the great thoroughfare to points south and west and ideas and styles got carried far up and down that route, southward to the Carolinas and over west into Tennessee and Kentucky.
Not sure if that helps, but hope it does!
Guy