Real shame those were lost. With a little more luck we could have had those two, plus a class 22 (at the expense of a warship which was provided as a replacement*), a blue Pullman, Falcon and maybe a baby Deltic. There’s been a few near misses in diesel preservation, though at the same time we’re quite fortunate to have saved a unique class 17 and 28 amongst others.
*D821 was provided as a replacement loco to BTG when class 22 D6319 was accidentally scrapped despite being earmarked for preservation - however I’d speculate that had this not happened and the warship scrapped instead there might have been greater motivation to save D818 Glory which was cut in 1985, so we might still have ended up with two warships.