I will be in the same boat soon. I have not looked yet but I will also need gray carpet for our 4 speed car. Ours looks to be ok but faded bad. I have used SEM landau black on black carpet with great success but not sure if they make it in the correct shade of gray. May be easier to just get new carpet if they make it.
The 1962 Jetfires all used solid color carpet sets that were molded. The Cutlass used a two tone or “salt & pepper” carpet set, also molded. I have not had good luck with the fit of aftermarket cut and sew sets. However, others might have done better or not been so fussy! The 971 trim used a gray loop pile carpet set. Fusick’s lists the cut & sew sets for 1961-63 in loop only which does not offer gray or silver. I have pics of the NOS original 971 carpet for a Jetfire attached (hard to tell from pics!). If either of you are as fussy as I am, I will send you a small cut piece from an original carpet to try and match with someones aftermarket set. Let me know.
I have never really looked close at the carpet in either of our cars till tonight. Now that I have I would agree that a molded set would be more correct than the sewn set if you can find them. Looks like my carpet is in nice enough condition that I can re die it and reuse it. That is if I can find a correct shade. Under my console and door seals still looks to have nice color so I should be able to match mine up.