thanks that's probably what's happening. I forgot all about the tin of lacquer having solvents in. Yes it would have impacted the wax. it will need a non reactive coat of something to protect the silver. ok time to strip the front and do it again.
Again, I'm not speaking from experience here as to how it will work with the ceruse, but if you make your own shellac (from flakes) you would dissolve it in methylated spirits, and maybe metho would be gentler on the silver/wax. It certainly is far less hot than lacquer thinners.

Mixing shellac for a sealer, you make what's called a "1 pound cut". This equates to a 1:1 ratio which is based in the old imperial language of 1 lb. of shellac flake to 1 gallon of *methylated spirits. (*denatured alcohol in the US terms)

You can mix smaller batches but use the same ratio. I usually go 250g flake to 250ml metho. It's not an exact conversion but close enough, and 250 mils of shellac goes a long way. It lasts me a quite a while.

If you have the ability to spray it, it may be better than having to apply by hand. I was going suggest Zinsser Bulls Eye spray shellac (rattle can), but looking at the MSDS, it appears to have some acetone in it as part of the thinners. Acetone and wax would definitely not be a good combo.

I'm probably not being much help to you here really