Easy with my resources. Your maker's mark is Lawrence's earliest, so checking my earliest Lawrence catalogue (1932) reveals the model 12; that likely wasn't made by Lawrence at all, but by Wyeth. Because this period is before Lawrence began issuing all-gunleather catalogues at the end of the Thirties, and at that time Wyeth specialised in making 'other peoples gunleather'.
The style is correctly called an Olive but often erroneously called a Mexican loop because that is the name that Heiser used for such: slits cut into the fender to accept the holster pocket. An incredibly wasteful use of leather, it likely derived from 19th century flap holsters, with the flap itself placed behind and then slitted to create an open-topped belt holster but without additional sewing or riveting.
Value depends on condition so you indeed will need to learn how to post images. Nevertheless I doubt holster valuations are part of this subforum's mission? Because this is far more subjective than it is for guns. Value earned depends more on WHERE you offer it for sale, with eBay yielding lowest prices and some online auction houses yielding crazy-high prices.
