Did piper ever use a single mag engine. I found a 1941 continental hand book that listed a A50-4 , A65-1 a A80-1 single mag. engine. In my collection of mag switches I have 3 that were made by Briggs and Stratton all cases and handles look like the A7 in shape and size only one is stamped A7 two are double mag the A7 has off -1-2and both other one says mag one mag2 and both one is single mag just off and on would anyone have any thoughts on want they might have been used on Thanks Steve