m141a/Bill,
I used two different web sites to post my problem, thought you might be interested in the responses from "Shooters.com". I'm still going to follow m141a's suggestion of growing old together.
Response 1: Go to your local NAPA auto parts store and get some of their spray gasket remover. Spray it on and let it sit for about 10 min. Then take a 3M scotchbrite pad wet with water and scrub it off. If your grips are checkered clean out the checkering with a toothbrush and water. One app. should remove most if not all of the linseed oil. let them dry and then you can finish sand them(400 grit) to prep them for the trueoil. Take care to keep your edges sharp, nothing shouts amateur like rounded edges. When applying the trueoil use another toothbrush to keep the checkering from filling up with finish. I usually apply only one coat of trueoil to the checkering on the next to last coat, and I scrub it in with a toothbrush to keep it flat, no gloss. Luck.
Response 2: The best way I've found is to use paint remover and 0000 steel wool. Wear good gloves and rub lightly (don't scrub it, just rub lightly) in circular pattern. This removes all the finish and leaves the wood alone, wipe off with cotton rags and repeat as needed till all the finish is removed. I've never used linseed oil but hear it darkens slightly and takes forever to dry. Have used tru-oil and think it's great. Am told linseed and tru oils have same main ingredient so you may be able to just apply the truoil over existing finish
Response 3: I have never used gasket remover or paint remover, but have used Easy-Off oven cleaner. I suspect they all do about the same thing. After the oven cleaner has blistered the finish, I take it off with OOOO steel wood and acetone. I don't like putting water on wood. On a plain linseed oil finish, a good scrubbing with acetone and OOOO steel wool will get it off. Acetone will get pretty deep into the wood to remove the oil. Breathing Acetone fumes is not good for you, so do it outdoors. I have used Tru-Oil for 40 years and like it very much. After you have filled all the pore and have a nice surface, use a fine rubbing compound on a soft cloth backed by a large pink eraser (you can get these in the grocery story). Be careful not do go to deep with the compound. Then put on a final coat of Tru-Oil, making one drop go as far as you can. The final finish will be glass smooth.