I was replying to the last post but also had in mind the earlier replies to you.
Aspen fuel is mainly used by gardeners it has a long shelf life and gives off far less fumes, I found it good to start the Arrow I only use occasionally but it is very expensive.
I like the pressure/vacuum tester you have seems like a good way to check the primary compression. I found mine was leaking by feeling the threaded hole in the crankcase front, there was a pulsing when the engine was running. Blocking the hole with a bolt cured it and made the engine a bit more lively.
The hole should be blocked by the cylinder spigot but it was still leaking.
The points system is OK provided the condensers are OK and it is not too worn, using remote condensers or even a Triumph back plate with points which can be adjusted individually is better.
I found my first Arrow engine would not start occasionally it turned out to be bits of rust from the double skin rear engine mount dropping into the carb and blocking the pilot jet. I used a fine filter over the carb inlet and dripped primer + waxoyl into the mounting to hold the rust pieces.