Found new owner
A pipe from our private collection purchased on the very beginning and pleasantly smoked until some larger and more expensive pipes arrived. The origin of the pipe is still not completely clear: the most of sources are not aware of this brand, Wilczak & Colwell directory refers either to J. Leon & Co Ltd or to Martin's Ltd, both in UK (the last suggestion explains the encircled "M" symbol on the shank). This is for sure a nice lightweight English pipe and it's made by a middle or large manufacturer which used own shape numbering system. Good smoker for reasonable money!
The pipe markings are "LEON'S \ CARLYLE", "416", "LONDON MADE", "(M)". The length is 13.5 cm (5.31"), bowl's height is 4.0 cm (1.57"). External diameter of the bowl is 3.0 cm (1.18"), internal diameter is 1.7 cm (0.67"). The depth is 3.5 cm (1.38") and this pipe weights 23 gr. Briar, vulcanite stem, no filter. We have patched a chip on the backside of the bowl, you may identify the trace under a good light.