MG Experts, your help please?

Brother in law got himself a mid 70s MG.  Looking underhood there are a couple things crimped off.

Anyone able to enlighten us as to what they are, and what kind of changes this would make to the tuning needed?  The SU carb is leaking right now, which is why it has a rag around it.

Now, a story.  His dad had a bodyshop.  He had one of these cars, he called it his donut machine.  Every day at 5 when he left for the day he would drive out and in the parking lot he'd rip three or four donuts as celebration for ending the day.

Accordingly, when BIL got it off the trailer he ripped a donut in the driveway before parking it.

The blanked off plumbing was EGR. No tuning changes required. Original carb was Zenith Stromberg. If replaced with SU it is a major reliability improvement. Keep doing donuts and you will soon be replacing axle half shafts!

The ones in the cylinder head are for air injection, you should be able to find some suitable plugs to blank them off.  The one on the manifold is for an EGR Valve.  I dont think either would affect tuning, they're for emmissions.

The carb should be a Zenith Stromberg CD150.  If it's leaking fuel, I'd look at the float bowl plug on the underside. 

I am not too familiar with the 1500s but on earlier cars that port fed the brake booster.

The crimped lines are for an air injection system that provided additional air to the exhaust ports. It was designed to assist in burning unburned hydro carbons on deceleration, The air was provided by a belt driven air pump and a diverter valve (the infamous gulp valve which failed often and caused the engine to backfire when shifting gears).

In reply to Trent :

Midgets never had a brake booster.