Ms. Pacs weren't silk screened, they were stenciled.
I think the black lines were silk screened - only speculation on my part though.
But you're right, they used stencils for most of it.
Silkscreening was my bright idea, as you know if you've ever dealt with Ms. Pac sideart, it's a "chase your tail" proposition, none of the vendors are willing to make stencils for the obvious legal reasons.
Twobits IMO is a gouging machine with their repro stickers, and I want to restore (which means "authentic" to me) this machine by painting the art as it was originally.
So, I thought silkscreening would be a viable alternative for the DIY'er. I just have to figure out what to use in terms of paint or ink and then how to color match. If I resolve the question of ink and the process works out, I will definitely document it here on the forum.