many years ago, like 1987, I made Susquehanna decals by printing oversize with a pin printer, reducing the black print on plain paper and then using a laser photocopier, printed the resulting reduction onto to plate paper ( coated and very smooth.)
I then brushes on a few thinned coats of gloss acrylic medium let it dry thoroughly and after cutting out the image, soaked and carefully scraped the paper off of the decal..
decal film is soooo much easier
I never tried using just lacquer thinner, but my suspicion is that one woulld have to add a coat of decal film liquid after the application of airbrushed thinner.