Me neither! Fig. 1.2 in the "Track" book shows BH rail on concrete sleepers on the Shrewsbury to Aberystwyth line in 2010. So it was definitely used on the mainline in GB. I think you are right though that "simple" FB rail was more popular in Ireland, which is worth noting. I think I'll try to model a good mix of the types. I may even model the CWR on Cork line as in retrospect, the track will be difficult to see and modelling it is easier. The pandrol clips are so low profile that a little drop of solder is good enough! For BH you really need the chairs for it to look right.