Car starts spluttering today, wont boost and kangaroo'd a fair bit.

Pulled over and found the plastic

'T' piece used to incorporate my boost guage has snapped

(how the hell could that happen??!!)
I've since sorted it so i havent got any boost reading and would like to know,1.

where is the best place to get a replacement and, 2.

do i need to buy one which has the 2 little brass inserts in?

any help much appreciated!
