Hopefully I can help with this because I asked the exact same question a couple of years ago on another forum. I had a Sako 85 laminate stock with holes that I wanted to fill, and also refinish because the lacquer was damaged in places.

Nitromors is rubbish these days, seriously don’t bother with it. The EU forced them to remove all the ingredients that actually did anything. You can however still get industrial paint stripper. “Synstrip” is one that I’ve used, but proceed with caution..I will as worried it would affect the glue sticking the laminates together, so in the end the old finish was scraped off. Very effective actually.

The stock was refinished by a friend of mine. The drilled holes were filled with a matching colour wood filler, somethings even filling the hole with 2 different shades where it crossed two plys. It was finished with Tru-oil, and flatted to a matt/satin buff, which honestly looks just like the factory finish. I was prepared for a disaster but it actually turned out superb, and I’m very critical.

Hope this helps.

Cheers
Greg