I have not heard of any one of those models. I would second all of Hutch's guesses, but I think the last could be either the 286SR or 289SR.
However, I wouldn't exclude the possibility that he got some one-of-a-kind prototypes that I didn't know about. I would guess there was a typing error with the SR model because the SR model numbers were never more than 3 digits.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9473.8 (as of 6/18/21)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR