Just a guess Anita - possible a vacuum gauge been fitted, no Idea why, more likely the pipe was fitted into the rockers to draw off pressure.
Some ( quite a lot ) of people seem to think there is an issue with A10/7 engines building up pressure in the rocker boxes, can't see it myself but each to there own.
there are four escape routes for pressure out of the rocker box back to the crankcase so my thoughts are a pressure problem in the rockers is a pressure problem in the whole engine and should be treated as such, never had any problems in this area myself