<<I've tried, without success, to find touch up paint for my Titian Red
87 Westy. I've checked local VW shops, googled, etc. and can't find
any.>>

Google for touch up paint?
Naw.
Try any local automotive paint dealer in your area.
Give them the paint code, and they will mix up the paint for you, and
gladly put in a aerosol can.
You can have ths all done in about an hour.