I've recovered/tolexed many amps and cabs and find it to be good fun and rewarding but I'm still learning every time I do it.
My experience with piping is this,...
It depends on the application. Around exposed edges, the piping I use has a "fan" or "tail". Staple and glue then cover the "fan edge" with your next course of Tolex or other covering. Seriously, the best thing to do (if possible) is to disassemble an existing product and reverse engineer their work.
In mid or exposed areas. I route an 1/8" groove into the wood and use the "fanless" piping. I usually tolex the cab/box over the routed lines, then before the glue dries, run an exacto knive through the the line and push the tolex into the groove. After wards, apply a light bit of glue into the groove and push the fanless piping into the groove. I like to use a roller like tool commonly found in hardware stores used for repairing window screens. I've picked them up for 4 or 5 bucks. It has a plastic handle and a couple plastic wheels on each end.
