I am interested in your varnish recipe also. I have made some with shellac and various other ingredients. The best ones used the hardest resins I could find, which are Ponderosa pine and Doug Fir and Alpine Larch.
Ponderosa varnish smells like vanilla. Be warned, if you make delicious varnish, you will be temped to lick your bow
This outfit has a lot of good supplies for the adventurous. Funny thing, a lot of the supplies can be used to make high explosives in addition to stains and varnishes.
https://woodfinishingenterprises.com