I did some additional research online and came across an entry of 10 rifles made for the 1956 US Olympic rifle team. There were 10 custom Model 52C's for the Melbourne games. It alos said it could be a possible prototype for the style D. It mentioned a fellow by the name of Karl Kenyon (does he sound familiar?), that made an Iternational Match version in 1969. However, let me give you some more details about it and if I get time I will take some pictures and email them. I need an address to send the pictures. It has a Marble-Goss (Gladstone) rear adjustable sight and a Redfield International Match front sight. The falling block has "Winchester" only ptinted, fancy lever, and underneath the lever it has Pat. Oct. 7, 79. Then it has the number 5 by itself. In a book that I might order talks about a serial #5 or #6 that may be rare. I think the book was by Thomas Henshaw on Old Winchester's. Otherwise I can't find a serial number anywhere on the rifle (barrel or lower housing). Any suggestions on where else to look for the serial number?