"loose" grips

[The Virginian]

I recently acquired a shooter grade Luger for about $700.00 that is an arsenal rework, but otherwise an 80% gun. When I took off the grips, there was a fair amount of rust under them and on the frame, with some even on the wood grips themselves. I cleaned the rust off and out over everything as I soaked the gun in Ed's Red and cleaned the grips with Murphy's Oil soap and got rid of the dirt, rust and oil that was soaked and embedded in to them. After they dried I wiped them down with a little linseed oil. The gun was reassembled and now both grip panels are loose. Do you think cleaning the gun and grips took too much rust and grime away so they don't fit properly? What sized rubber washers do you use to tighten the grips up or is there anything else besides hot glue or tooth pick I should try?