The first 3 part one is Chartered Industries, Singapore. (Now called Singapore Technology Kinetics.)
G denotes 7, A denotes 1 for 71, meaning 1971. B is 2 , C is 3 etc. GG is 1977. Codes have been observed starting with G (1970’s),
H (1980’s), J (1990’s) and N (2000’s).
The second looks like an Italian h/s on 7.92 Mauser rounds sent to Egypt.
Jon is right, the 7.92 56 headstamp was made by Bombrini Parodi-Delfino and packed in boxes labeled "50 ROUNDS 7.92 mm BALL/AP/TRACER LOT SIPE** /56" (= different lot numbers). SIPE are the initials of the powder manufacturer (i.e., Società Italiana Prodotti Esplodenti).
If the primer sealant is black this is a ball loading, and if it is green it is either AP or tracer (correct code for the latter should be red, but these were loaded in AP coded cases).