Use grease, not oil. Wood stocks should be sealed against moisture with any wood sealing product.
Saw your post about Lee-Enfield Parker Hale sights. Don't have permissions to respond there. Only place I saw Lee Enfield No 4. Parker Hale 5C Aperture Sight was on the evil that is E-Bay at $350US. Same guy(in South Africa) has a 5C for $230US. Sarco is selling incomplete PH sights too.