I worked on a couple of B-1 for a couple of brothers who are Allis collectors. The engine should be a Model 19 B&S. What I did to both of them is replace the coil with my coil modification. The coils on both engines were bad because the B&S P/N 290880 coil will go bad sitting in a box on a parts shelf. This coil the last time I checked was about $130.00. I use a later model Briggs point type coil by modifying the core. You can find the info in a Nov. 2005 issue of Gas Engine Mag. You can also find the info in the files section the the Briggs group on Yahoo. You need to join the group to have access to the files section. It is under the title magnematic fix.