Nice summary.
Several parallels with:
Clipper 160 / 3Nov73 Cargo B707-320, N458PA departed JFK with 15360 pounds of 12 different hazardous materials and other cargo (payload = 52912 lb), bound for Scotland and Frankfort. \\ Crew were offered no notification of Hazmat aboard.
That cargo-B707 crew overflew usable airfields in an attempt to return to BOS; smoke in cockpit; then eventually LoC near airport:
P.C. = smoke in cockpit, continuously generated, smoke led to emergency situation and loss of control during final approach, when crew (in un-coordinated action) de-activated the Yaw Damper, with incompatible configuration of Extended Flight Spoilers and Extended Flaps. AAR included reports of witness-pilots' observation of accident aircraft in unusual attitude. [ICAO "AAD"; and Air Line Pilot May90, CV Glines' Hazmat article. AW 102:47+ Mr10 '75, 51+ Mr 24 '75, 57-9 Mr 31 '75.]]