Since I bought my first Victor Special in 1970, I've wondered what tool should open the toolbox. Typical moment 22.
As it was quite cold last night, -18C, I decided to charge batteries in them.
Finally solved the opening. A small square piece of 1.5 mm thick stainless, 16mm wide, 40mm long with a hole for the keyring.
Only took 53 years to figure it out.
I have the same motorcycle and had the same issues wondering how to access the tool box.
I now have a repair (penny) washer in the pocket of all my motorcycle jackets.
I've since realised it also works for covers on my other motorcyles.
If only the bike magazines still had the guinea gimmicks columns.