IIRC, this is a very desirable shooter. Isn't it identical to the "Mountain Gun" series only with the Springfield logo? 45 Colt? I remember reading about them and keeping an eye peeled, but can't recall the exact specifics.
Also all .45 caliber Mtn. Guns have MIM parts and non-serrated grip straps.
I have a 625-6 Mountain gun in 45ACP. it has min parts, no IL. frame mounted firing pin. Replaced trigger with flashed chrome one. My first MIN gun. Was always weary of them, but this one's smooooth as butter!
Goes good with my 4" 625-3 and 25-2. Might say I like 45ACP revolvers.