When they eliminated the 'self improver' route, they gave PPL AFI/QFI's a Basic Commercial Pilots Licence (BCPL). I've often wondered what happened to holders of these licences. Were they later simply given JAA CPLs?
These two events did not happen at the same time. (Restricted) BCPLs were given to PPLs who were earning money instructing. This happened in the late eighties/early nineties whe they changed the rules and a commercial licence became compulsory to earn money while instructing. (Don't know the exact year, I started flying in 95). Most of these guys and gals still instruct on their BCPLs. What happens to them when they need renewing I do not know.
The 'Self Improver Route' disappeared when JAR came in. Basically, if you had enough hours you were exempt from approved training. Technically that meant you should just be able to do the IRT, but you weren't allowed to do that unless you had got that bit of paper known as the 170A. Most schools authorised to give out those things wouldn't do so until you had a number of hours training under your belt since a failure would affect the statistics.
In '96 or '97 the rules were changed to allow anybody who had 100 total time to sit the ATPL exams without any requirement to attend a course. So get PPL, do ATPL exams, get BCPL and AFI rating (as it was know then) by about 200 hours total time, instruct until you hit 700, do IR and get CPL/IR issued. You could start the IR training a bit earlier (650 comes to mind) as the 700 hours was a requirement for licence issue.
Self-improver and 509 lead to the same discussions we now have about modular vs. integrated. It is generally accepted that it doesn't make a f
g bit of difference since you all end up with the same licence in the end.