I've been using https://www.the-blueprints.com for ages when I am building and or scratchbuilding stuff. They have a lot of blueprints, drawings, profiles and whatnot of just about anything you can think of. Most of it is free, but there is a payed feature to get some drawing in SVG format. Personally always could find anything I wanted/needed from the free stuff.

TTFN,
Rob