I stayed up late tonight and finally got the toner lacquer applied to the trim. I masked of the veneer areas and applied three light coats. Then a few extra spurts on areas that were still too light.
Next up - grain filling.
I haven't used this Constantine filler before but I've heard good stuff about it. I'll practice on some scrap veneer first.
According to the ingredients on the can, it's ground quartz, linseed oil and a few solvents. It takes 24 hours to fully dry.