you called?
I have 2 Zieleman, and that was a 20+ year search although it's gotten much easier
with the advent of the internet.
What size bike do you ride?
Are you set on a Zieleman or RIH, as there are quite a few other
Dutch builders all little known and most producing real quality frames.
I updated Dale with the fact that Zieleman stopped building in the late 80's
but the shop is still open. Ko's son-in-law runs it and mostly does neighborhood
type repairs.
RIH is closing up (if it hasn't done so already) so that will be the last of the
small Amsterdam builders which is a real shame, atmo.