The demolition was typical of its time. Roads and brutalist architecture were seen as forward thinking and historic buildings were just in the way. I suspect brown envelopes of used bank notes helped in many cases. The was a saying in Birmingham, "what the Luftwaffe started, Frank Price and the city council finished". As well as Snow Hill, New Street was modernised and a Georgian crescent was one of many victims of "progress". Still Worcester faired even worse.
My personal favorite would be the 1970s Woodhead Line with CL506s and CL76s JT should really consider the mid-80s Furness/Cumbria Coast line or the North Wales Coast line Another modern-day route that DTG should consider is either the GEML to Ipswich or the West Anglia Main Line, with the branch to Stansted.
A late 70s Woodhead would be great, the TSC classic BR Blue version of the old Woodhead route was excellent. Also if we had the 506, that would make a good starting point for a 306 should an older GEML be made.