To help, here's the order of events:
I didn't have any SSL installed until recently and, using IBrowse, I was getting errors when accessing websites which need to run in https.
I installed Amissl 3.6 and then upgraded to the latest package for version 4 off Aminet but still get errors in browsers (mainly tried Ibrowse but also Aweb)
I've then tried MiamiSSL but can't get the encryption key installed/recognised which was the trigger for this thread.
I probably won't get a chance to try again until the weekend so will update you when I've tried the new advice. Overall this is a hobby machine which I want to play with and get working as well as possible, I just like to see what my 25-year old machine can do; it's not stopping me from doing anything critical.