Most gun shops. Your Iver J is in caliber 38 S&W, which is NOT .38 Special.
Most of the Iver Johnson .38s were in caliber .38 S&W, not .38 Special. The .38 S&W is shorter, slightly fatter, and less powerful. Check with large gun stores.
Online! Search Iver Johnson information; There are forums that have experts or links to answer any question you have. I have yet to find a single source for everything Iver Johnson...
Try Numrich Gun Parts at the related link.
I can find no '65A' but they did make a 55A, eight shot revolver from 1961-1978. Value of the 55A, depending on condition, would be $95-$225. Later models had 'Iver Johnson Sportsman' on it.
Possibly Numrich Gun Parts of NY.www.e-gunparts.com
Numrich (Gun Parts Copr.) has some Iver Johnson parts.
The only Iver Johnson Model 50 is a .22 revolver. The only Iver Johnson 9mm Parabellum (Luger) is an M1 carbine sold in the mid 1980's. IJ did sell the Pony which is chambered for .380 ACP (also called 9mm Kurtz, 9mm Corto, and 9mm Browning short).
sorry icant answer your question. i have a Iver Johnson 8 shot cadet model 55s serial# c27518. and i cant find any info either so don't feel bad. i do no they were manufactured from 1955 to 1978.
the 'bluebook'
The gun was manufactured from 1919 to 1957. A box will be tough to find but it may be out there. Brouse eBay frequently.
gunpartscorp.com has the best collection of Iver Johnson parts
It may be difficult to find specific replacement handles for a vintage pistol like the Secret Service Special by Iver Johnson. I would recommend reaching out to gunsmiths or firearm parts suppliers to inquire about the availability of replacement handles for this particular model.