No such model in the Ruger line.
Ruger has never made a model with that number. You might be referring to a RG, which was made in Germany. No sn records.
The ruger model RG23 CAL 22 LR is between $25 and $45. <><><> Above is correct. RG does not stand for Ruger. It is a German abbreviation for Rohm Inc. These were German handguns of very low value and indifferent quality. Please have examined by a gunsmith before attempting to fire.
20-50 or so
15-50 USD
25 USD
Inexpensive. @ 50-60's
$25-$45. Low dollar firearm of indifferent quality, no longer manufactured.
http://www.oldguns.net/q&a8_98.htm
30 or so
I believe what you have isn't a Ruger product, but rather, a Rohm Gmbh revolver, manufactured in Germany, and imported into the country by R.G. Industries. The RG-23 used the .22 Long Rifle cartridge.
I do not believe you have a Ruger, but an RG- Rohm Gemeinschaft. Two very different companies. The RG is generally a low value, low quality firearm that was made in Germany. Value is based on condition, but may be $25-$75.
$25 or so. Low value handgun.