Bristol F2s were all scrap long before 1940 but all the ex bombers in use for training, target towing etc. had their bomb racks reissued and light bomb racks issued for basic trainers eg Tiger Moth. I knew a TT Westland Wallace pilot whose entire unit asked to be sent to Fighter Command as experienced pilots but were refused being told they were needed to be able to bomb any German invasion.
So, yes, Sealion troops would have seen a crowd of varied biplane bombers of all sizes from Heyfords to Tutors as well as the normal first line Blenheims, Battles and Lysanders and heavier Whitleys, Wellingtons and Hampdens. But not Bristol F2Bs. This is not normally factored into Sealion scenarios so it would have been even more unlikely to succeed than is normally thought and involves hundreds of extra aeroplanes.