I'll give you my 2 cents but ultimately I'll leave it up to you to decide -
I'm not a fan of the 97 last - many of the lasts just "don't work" for me - this one "works" but not well. I wear the same size in this as with everything else, and the toebox just feels ultra cramped. I tried on (pretty sure) all of the iterations of the Grayson, including the Manchester. With the Grayson, I can wear them a full day and while they aren't comfortable, I can get by. With the Jermyn (which was out at around the same time as the Manchester), I'm usually in pain half-way through the day. Same size, same width. The Manchester (and Westchester for that matter) had the fit of the Jermyn, not the Grayson. People can disagree, I'm fine with that, but I feel like they definitely relaxed the fit when it came to the Grayson.
If your Graysons are completely comfortable and you feel like you could tolerate a width down (meaning you order a D and it fits like a C), I'd say place the order. Personally, if they had a Westchester in shell for sub $300 (which they did have in some sizes), I'd pass with no regrets whatsoever.
Also wanted to note, going from D to E (which I did try with the Manchester) messed up the heel fit completely.