I have an Army Special with a serial number 489XXX made in 1922. Yours is the same vintage. I only paid $150 for mine, but it has had a hard life. It is nickel plated, but it left the factory blued. The plating job almost obscured all of the markings. The only reason I bought it was that despite its appearance, it locked up tight, it was a .32-20, and I just had to have a gun in that caliber. I went to the expense of having Colt letter it, thinking I might be able to trace its life and write an article about it, and hoping it had originally been sold to the Shanghai Police Department. Alas, it was sold to a store in New Orleans that no longer exists, and when I went back to the gun shop to ask if they could put me in touch with the former owner they refused, so the gun's life is a mystery. Even the gun's title is ironic, because no army ever bought it.
In my research excursion I learned that 1920's and 30's jazz musicians' girl friends often carried .32 caliber revolvers because they were easy to keep in their handbags. As a result, some musicians used a brass-backed guitar with the thought that if the girlfriend shot at them, it would stop a .32 bullet. There's even a song called "The .32-20 Blues" recorded by Robert Parker in Texas in 1934.
1) The Colt Army
Special was meant to take the place of the "New Army
" model in the Colt line-up. It was chambered for the .38 Special, rather than the .38 Colt of the New Army, found to be ineffective in the Moro uprisings in the Phillipines. By 1926-ish, it was obvious that the Army was not going to be buying any more revolvers as their main handgun (they only bought the M1917s as fill-ins when need far outstripped supply of M1911s in WWI), so Colt, at the time they made some small changes to the AS, renamed it as the "Official Police", hoping for large scale orders from PDs, rather than the Army.
2) "32-20 Blues"- Robert JOHNSON. .32-20 was fairly powerful for a .32. In Johnson's song, he says:
"If she gets unruly, and thinks she don't want do
Take my 32-20, and cut her half in two
She got a thirty-eight special, but I believe it's 'most too light
She got a thirty-eight special, but I believe it's 'most too light"
He apparently considers the 32-20 more powerful than the .38 Special. And I don't think a brass plate would stop a .32-20.
3) Shanghai PD never used .32-20, AFAIK. Three-eighty British (equivalent to our.38 S&W Long/.38 New Police, but with a 200 grain bulet), I believe.