Thanks guys for the advise. Still need help.

1. I Pulled off the hoses and looked inside the rad. NO, I mean no evidence of any corrosion. On other vehicles I have owened, I have seen a white build up at each tube inlet. But nothing on my MB.

Question: Should I see evidence of the blockage? Help please.

2. I felt all over the rad and it seems pretty cool all over.
3. Again the hose that attaches half way up the drivers side is cool also.
4. The rad does look original though, I can see some external rust at the top of the rad.
5. Looked inside the hoses also, no build up on the inside support coil either.
6. Rad Cap looks good, when I squeeze the hoses I do not hear any air leaking from the tank.

I know 99 deg is not that hot, but I want this thing to last.

Action Plan:
A. Wait to hear if corrsion should be easy seen in a blocked rad
B. Re-check cool stops on Rad, may corners are hot?
C. Investigate if Water pump impeller could be issue?

Thanks again,
John