Gil I do not think you will get very far with this .Belive me I have tried ever trick in the book and a few that are not to try and do what you want . Nothing I have done has made ant noticeable difference

Reference to wagon wheels whilst interesting is a different ball game ,these are made up of diferent peices and diferent woods ,look at Constables famous painting "The hay wain" wetting the wheels to swell them .Wont work on a gun stock .Unfourtunatly.