You might try Googling “Microscale 1/87 (HO?) scale White Gothic” Measuring McCudden’s B4683 from my Encore decal sheet gives figures approximately 5mm tall by 2mm wide.
Alternatively, you might look for dry-transfer (Woodland Scenics, etc) sheets. In my experience, you can rub them onto clear decal paper and apply the result as any wet transfer. It doesn’t even require clear coating of the resulting decal before application.
Hth, Rob