Can you recommend any good sites of handmade bike / bike part manufacturers?

Thanks

Have a look at bespoked.cc the site for the show that was just on this April. Scroll through the list of exhibitors and check them out.

In a similar vein to tang – here is a link to the original American Handmade bicycle show:
http://www.2015.handmadebicycleshow.com/ (change the year to see archived versions).

If you search for news articles on these shows, you’ll see lots of stuff come up with show reports.