I think the replies to my orginal post have been outstanding and have shone a liight on both Midi as well as its its use in BiaB. Since I posted the initial issue I have also been examining the files and I can see some the problems now. The tempo map mentioned by Charlie was of particuar interst with regards to 'Abide With Me' which is clearly a live performance suited to the occasions when it would be performed.

I thank everbody very much for bringing a lot of light to this partiular topic for me. It has helped me a lot.