I guess by about 1972-73, i.e. when BADP and BADR were delivered, the Advanced was the standard production variant. Did any other early 737 customers, e.g. Aer Lingus and Braathens, also order the Advanced ? Both these airlines were regular or semi-regular users of LBA's short runway in the 1970s, albeit not flying long distances. Their early 737s should therefore have been able to cope.