Temp readings

[subman60]

I know everyone is probably tired of my ?s about my car but please bear with me. I hope this is the last ?s I have about this subject. My 82 240d's temp gauge has been showing it running hot so I've done everything I know of except changed the waterpump. After posting a ? about changing the pump I felt it might not hurt to take some temp readings. I used a IR temp gauge which I know isn't probably the best method but it's what I have. So at idle my cars gauge will go all the way to 120c. This is after the car has sat running for about 10 to 15 min and stays there. I shot the top radiator tank by where the inlet hose attaches and got readings between high 70 to mid 80c. Then shot the bottom tank and by the supply hose and got readings between mid to upper 40c. I also took a reading where the temp sending unit is on the block (in between the glow plugs, I hope that was it). I got a reading of between 80 to low 90c there. I also took readings where the top hose hooks up to the engine block and got pretty much the same reading at the top of the radiator. My ? Is does it sound like my temp gauge is off and do you think it's safe to drive somewhere close to home (1/4 mile or less) to have someone verify my readings?

Thanks,
Mark