Let me be the first to congratulate you!
Any idea what the adhesive was that a previous owner used to impair your ability to properly repair your Rover?

 

And now the question is whether or not the plenum orifice is damaged beyond being usable, i.e. will a replacement pipe and new O-ring be able to seal effectively?

 

Damn, that's hella ugly.
I'd also be concerned about getting a seal on those surfaces. I'm assuming that leakage is the reason that you started this whole adventure, so you'd essentially be right back where you started.

 

You won. Again.

 

...thanks NickAdams! ...and nope, it seems nothing was added, it might has yet been time, heat, water, coolant, and a heck of bad luck! ...but is out!

 

...I guess you're right MLN01, although the orifice does feel to be in good shape. I presented the replacement part and it does go in - with an old O-ring- with a good fit, so I'm hoping that it would seal better with the new one. I'm also planning on putting some "Leak Lock" to the pipe when finally putting it all back together.

 

...pic does look more dramatic than how it actually is Mollusc, but I'm confident it will seal good and stop the leakage that I set out to fix, what an adventure! ...but again the orifice does have a nice feel to it, and we only worked on the part that stayed in and had to remove... the outer part did received a beating, but it's just cosmetics! ;-]#

 

...sure did Charlie_V! and soon you'll see how the cleaning situation is coming out, everything looks pretty awesome, and hopefully will work that way too. Once all is clean I'll move onto putting all back together and finally give the heater return pipe it's do or die test! ;-]#

 

"Pop quiz, hotshot. Do I pull, twist or both to get the "oil separator" out? and, Do you know the specs of the bolts that hold the "Coil Pack" assembly in place, mine is loose, just sitting there? what do you do? what do you do?" ;-]#

 

Oil separator pulls out from the bottom on some years and the top on others. What year is yours?

Those little bolts. I don't know the specs but they fall all of the time so it would be good to know. I know they are the same as the bolts on the fuel rail (but longer) but that's no help because those are buried deeper. I'll see if I can find an extra one and have the shop tell me what it is, unless someone else knows. The have to be an M2 or M4 with 1.25 or 1.50 pitch about 5/8ths (inch) long.