T-Piece woes

Evening everyone, hoping that someone can point me in the right direction with this problem!
I have an 87 Cabby GTi with the DX engine and there is a T-piece that connects just in front of the manifold that connects to some vacuum pipes that run left and right. This has something to do with the idle-not sure how it works though?

The problem is the T-Piece has broken which is leaking air causing an erratic idle. I've tried replacing the T-piece but it turns out that this particular T-piece is a reducer on one side and I cannot find anything that works.

Is this part still available, or does anyone know where I can get one?

thanks in advance!

Is this what you are talking about?
https://www.mecatechnic.com/en-GB/_C017953.htm

That's the one! Perfect
Ive never ordered anything from overseas though, is it safe? I've tried to find it in the UK but no luck at all-seems a very rare part!

Yeah just order it, I buy from all over the place. 

quick google of p/n gives you:

https://www.vwheritage.com/classic/?ClassicLookup=067103693

think in stock - didn't try adding to basket: