If you want wood finish to last use what wooden boat has been doing for well ... a very long time.
Once wood old coat is stripped and fine sanded as best possible apply marine varnish in several steps: start with first coat of 10% varnish + 90% compatible solvent. Let it dry although it will never completely do. When possible sand down first coat as best possible (it is sticky so only so much can be done) and apply second coat with 30% varnish mix. Same wait and sand, coat with 50% varnish. Then over again with 70-80% varnish. Once you get to 100% varnish ensure at least 2 coats are applied and pay particular attention to sand everything as best possible before next coat. In fact once you pass 50% varnish mix it will be hard surface to sand well.
BTW, above is a short version, old standard calls for 10% increase between coats, so 10th coat when you use 100% varnish. This whole process give such great results because it allows varnish mix to penetrate deep and harden below surface making top coat not as prone to chipping.
The end result is hard, long lasting varnish coat that is resistant to damage, has perfect finish. This when used on wooden boat lasts a long time in very good shape, which is remarkable given environment boats are in. If you don't like shiny, use semi-flat varnish.
Linseed oil is OK, there are much better mixes of oil then pure linseed.