The civilian Winchester 52D stock has a varnished finish with no rear sling swivel. My CMP Winchester 52D has a oil finished stock with a rear sling swivel. Answers came from Culvers and RFC.
If the"oil" mentioned in some posts is tung oil or linseed oil then you may be describing the Winchester finish. It may have been varnish but I could never duplicate a winchester finish using varnish but I can if I use tung oil. A correctly applied tung oil finish can be either glossy or satin.
Thanks to all! There is a nice thread on Culvers , that explains much. Never thought that most was diped finished in oil vats. Have got information from BCF, RFC,Culvers, and CMP. Before computers, there was NO WAY to have got this much information , so quick.