These are all early post WW 2 production S&W revolvers. 3 of the Terriers have leaf springs considered as I frames. 5 of the Terriers have coil springs and are considered to be IMPROVED I frames. The 32 hand ejector is a true I frame, it is in the middle of the group. 1 of the Terriers went to US Post Office, I have invoices for 3000 purchased by PO between 1950 and 1952. 1 Terrier went to Sacramento CA. P.D. and 2 went to New York City P.D.