Even better would be to remove all or some of the keys and put a base underneath the typewriter for more potting soil so you can have succulents growing out in between the keys.
This home in Edinburgh, Scotland, has a living lounge set up outside the front door with succulents growing out of a wingback chair, a vintage lampshade and teapot, and, of course, a classic pair of boots!
Seriously though, old boots, shoes, and similar items often already have drainage, and if they don't, they are a much easier material to poke a hole in than something hard or ceramic.
These examples involve different ways you can dress up your tin can succulent planters using other old bits and bobs you might have lying around, from left-over paint to bits of fabric, lace, or ribbon.