In order to ensure all tools and gauges were kept within the correct tolerances, Winchester employed the use of direct 1:1 model of rifles by which the various gauges could be calibrated. Maintaining these strict tolerances helped to make sure that all parts would be correctly interchangeable. Model and tool ro0m guns such as this one were a cornerstone to Winchester's strict quality control standards. This particular model gun is pictured on page 203 of "Winchester Slide Action Rifles: Volume I" by Ned Schwing. Manufactured without sights, and left completely in the white with correct full length barrel marked "MOD 90 S&L (meaning it is chambered for both the short and long .22 rimfire cartridge)/11-28-17", "", and "RF" at the breech end. The left side of the Third Model receiver is marked "M90" as is the takedown screw, and slide bar cover. The magazine tube between the slide handle and receiver is marked "14 BMRG/2-9-16/SA". The slide handle has the correct 12 grooves and is machined steel. With plain straight grip stock and crescent buttplate. The trigger guard has a lead tag marked ".616" and a second brass tag marked "9/ANIS/WINCHESTER" attached with a small brass loop.