First proper job, first fail!

Thermostat first "real" job to tackle. Fuel filter, rust painting etc.. has been a bit micky mouse. Replaced first indicator bulb too. Brake lights not working, need to fix that as well. But by real job I mean nitty gritty stuff.
Drained rad down from the bottom hose, the drain tap is stuck, apparently that's quite common. No problem draining from the hose.

Had soaked the nuts with WD40 for a couple of weeks, and sure enough they came off pretty simple.

All went well as per picture.

But, will the damn thing budge? No.

Didn't want to be too gung ho, without a backup plan, so put everything back as it was for now. Have ordered as new housing, just in case and will try a bit harder next time! Need to get a thermostat in for winter!