Petts Wood Station used to be the terminus of route 94. I think that half the service went on to Orpington (but possibly not on Sundays). The buses used to swing round in front of the station steps - an RT could do it, an RM just about.
Yes, about half the weekday service on the 94 extended through to Orpington. It was 1990 before the Sunday service on the 208 extended to Orpington.
The scheme in September 1982 was a bit complicated -
It involved the withdrawal of the 94 (which didn't pass the door at either Catford or Bromley garages), the 47 was withdrawn south of Bromley Garage - during the week, the Farnborough end of the 47 ran mainly as a local service (operated by Bromley garage) Lewisham (Surrey Docks on Saturdays) - Farnborough, or Surrey Docks - Farnborough on Saturdays; and the 229 was withdrawn between Green Street Green and Farnborough and converted to OPO at the same time (I think the Farnborough 'George' terminus wasn't suitable for OPO buses - from memory, you boarded in the middle of the road, which was easier with open platform buses).
The 208 took over the Orpington - Bromley section of the 94, then ran via the 47 route to Lewisham (and on Saturday daytimes on to Surrey Docks)
The 261 took over the Lewisham - Bromley section of the 94, then continued to Farnborough via the 47, then to Orpington via the 229. (The 261 also continued the 94's Saturday extension to Brockley Rise.)
The 208 was initially operated by Catford and the 261 by Bromley - both routes passed the door at the garage, cutting out unproductive travelling time in crew duties.
The 208 and 261 are currently both operated by Bromley - the 261 having lost the Orpington end as part of the 'Roundabout' network scheme - it's now part of the 358.
Broadly, it's TfL policy now that scheduled short workings/ part routes / routes running in sections doesn't happen (there are a few exceptions), but a number of locations are authorised for unscheduled 'curtailments'. I'm not sure if the 208 still has such a point at Petts Wood. (Petts Wood Station was unusual in that the 94 and 161A both terminated there, showed the same ultimate destination, but terminated on opposite sides of the railway.)
Thinking of this, there were a few routes - certainly in to the 1980s - where buses never or rarely ran from one end of the route to the other, being run wholly in sections. I think I'm right in saying that when the 12 ran from Croydon to Park Royal, there were no through journeys end to end. And I can remember trying to get to central London from Forest Hill on a Saturday around 1980, and didn't quite grasp (I was quite young at the time) that you needed to catch a 12 and change to a 12 somewhere north of Dulwich...
And at one point the Saturday service on the 141 ran in two sections that didn't touch (Wood Green - Moorgate and Farringdon Street / Elephant - Grove Park.)