Noland mentions in his Vol 2 under the '65 that he found vent window glass dated with the code CGP. There is nothing more mentioned. The NCRS Tech Manual lists dates, but not exactly that way. There is a CG for Nov '64, but no reference to a CGP. Is the "P" a service replacement, or something just used on vent windows, or what? I have searched the archives with no luck...Thanks...Dave