Diesel Overheating... Help!

[AjfromColo]

I took my 82, W123 300D in to my local MB garage as it gets to 100 - 105 with no problem. Yes, it's hot out -appx 95f. And yes, I had my A/C on. But talking to my mechanics, it should not get that hot. They suggested that for a 25 year old car, I should replace the radiator and t-stat. I had them do the water pump at the same time. After all repairs, it still stays in the same temp range. Can anyone assist? What am I missing?
Will submit all answers to my MB mechanic. Thank you!