Hi Peter and Pete,
Actually - I own two serialized HKs which may provide the "book-ends" for these serialized HK's. No's 2053 and 2284. These are an Early "S" and a Mid-range "S". In my database - I also have had the pleasure of verifying three HK's within 35 Digets of both Peter's and Pete's HKs. While both Pete's/Peter's are late "S" code - overlapping serial ranges are NOT uncommon in Krieghoff production. And other HK within this range also include a Late "S", "36" and another Mid "S".
I just want to note this for other HK Collectors who may be following this thread. While Mr. Gibson's excellent research is the foundation of Krieghoff collecting today - please be aware that basing a Krieghoff variation upon serial number is incorrect, given how HKs were manufactured, pulled and sent to fulfill the original contract. Rather, it is more correct to establish the variation on the markings, proofs and toggle type present upon the HK - rather then simply referencing the serial number range to Mr. Gibson's work in trying to establish which "group" your HK may be included.
Again - both Peter and Pete - wonderful HKs.... Thanks for your posts, information and pictures..!