I was looking under the hood of a friend's '84 wagon, and I noticed that there were two things different from mine:

1) the Alda switchover valve (the one near the brake cylinder on the firewall) had been bypassed.

2) The black plastic transmission vacuum box on top of the engine (the one that contains the little white levers) had been removed.

Why would someone have done that?

Are those modifications potentially damaging to the engine or transmission?

Is there any reason for my friend not to gather the parts to put those things back the way they should be, and will there be anything particularly difficult about finding the appropriate parts and putting them in?

Thanks in advance,
Michael