I was watching an old VHS(!) of Crompton workings and that featured two TC sets in the formation, both in NSE livery but I had to rewind the tape just to double check I was not seeing things, sure enough there were seven cars in the formation with the 33 at the back, the first TC had only three cars so they weren't unknown to run as a 3-TC presumably when the TCF was out of use for maintenance I presume.
Newhaven Marine springs to mind, indeed it still fits into that category. It still had a parliamentary train even now but no one can actually join or alight there anymore due to the dangerous state of the station buildings, a taxi would be provided for any intending passenger to meet the train at Newhaven Town. All thanks to the lunacy that is the rail regulations dreamt up by some 'not on this planet' civil servant in a locked basement in Whitehall I presume!!