Update.
@pizzaguy @onehundred80 1. Yes. I told them to stop touching the car, regrettably apparently, they did not listen. They went ahead and replaced the radiator without my written approval, and lo and behold hey suddenly they noticed the fan wasn't working. (HOW they did not test that the first time.. lets not go there.) and suddenly they find.. what you suggested and I had forwarded to them PRIOR TO ANY work being done.. several of the articles from the forum here. What do they do? Run the same tests that you and others suggested here AFTER suggesting doing these when I dropped it off. and OMFG.. suddenly a 50 amp fuse has to be replaced, and my my look at that, the Top works, The power seats work, all of the sudden electrical problems work.... that they "couldn't' find" that frankly a simple evaluation of all electrical systems which I just didn't have the time to perform, would have shown the fan wasn't working, which would have led to the replacement of the fuse, and most likely, a happy radiator.

Yes we had a "civil" conversation and I am being reimbursed for the "diagnostic" and I will pay for the radiator part only. Never to see them again. The car will be back in my hands this AM and yes I have ordered my own tools and
Now just so you all know I do not have the time to work on the vehicle as I would like and I do not have the trained eye to restore a 5 year old sitting car, that is why I trusted those that said they have worked on SLK systems for years, and several people referred me to them. From this point forward I will do as much as I can on my own and yes I am a (previous) certified HVAC Tech / Installer so I have a clue about engines and heating / cooling systems.
And I do take advice from those that have more experience than me, that is how you get better.

"Never take fitness advice from people who are less healthy than you."

Next steps:
1. Full test of all systems once more. Find the most important issue and fix that first.
2. Do #1 first then figure out whats next.