Thanks Bruce,
I have a shop near me that sells birdies so should be able to order part. I am also trying to finish my bullbar Brompton off.
is that your dualdrive birdie?
Thinking of doing this and adding bullbars, and brifters; my usual preferred mod on folders ( I have a dahon androes stem for the job.)

I think play problem (2) could worn bushes ?? that should be straight forward.
Problem 5, Do i need to order a new stem or part due to wear? play is only slight, but in my experience is that birdie stems are play free ??