If i was in your position i would do as someone said above, remove thermostat.
Warm it up, do a skid and see if it gets to running temp.
My MR2 does and i can vary it with the two electric fans.
Could also jimmy up a water sprayer. Intercooler water spray makes massive difference, id say it would on a radiator as well. After a shower stand in front of a fan and you will see how fast you freeze your ass off. Just dont get caught in an awkward situation lol.
Also need to be 100% sure the system is functioning as it should. ie nothings blocked.
I like to take the thermostat out, put about 1/4 cup of dish washing liquid in, go for drive, leave it over night, go for another drive and then dump it, flush like hell and put it all back together. Amazing what comes out with the detergent added after it has already run clear. Solved my overheating problems.
-Simon