The 31 T6H-5307N's that were delivered in 1974 were numbered 591-600, and then 301-321. However, when the buses were painted and numbered by GM, #s 301-321 were given #s 601-621. Rumor has it that the first LRVs were supposed to take the 600 series, so these were renumbered to 301-321. Of course, the LRVs ended up taking the 1000 series instead, so this definitely made for some confusing numbering when the 1976's (#s 397-399 and 601-697) showed up! These 31 buses were the last ETS buses until 1981 to have standee windows, and the last GM buses to have folding rear doors (the Flyer E800's built from 1974-1976 were the last ETS buses with folding rear doors). Units 591, 592, 593, 310, 312 and 314 were sold to Fort McMurray in the mid 80's. 596 was scrapped after an accident, 309 was sold to Busex in 2000, and scrapped in 2001. 319 was out of service, but returned for the 2001 Track and Field games, and then was sold later in 2001. 317 was retired and sold at auction. 316 was auctioned off in 2001. The last units in service were #s 597, 301, 302, 303, 311, 315, and 320, all of which were retired in mid-to-late 2007. #s 317-321 had hard shell seats, the only ones on an ETS GM bus (Popularily referred to as "The McDonald's seats" due to the beige fibreglass frames and red + green vinyl inserts)! #s 597 and 320 were the only units rebuilt into the blue and silver ETS scheme. #320, being one of the first blue and silver rebuilds, recieved a few variences such as small fleet numbers, all-silver doors, and anti-glare black paint around the driver's area.