MVT Area Meeting + Truck Problem

The MVT Area meeting I wrote about on the 12th Jan went ahead, and was quite a success I feel with 26 (including myself) turning up. Ratified a constitution and talked about forthcoming events (shows and the like) along with ideas for a 'Spring Run' out in our vehicles. Talking of which the group owns a real mix, with a varied range of Jeeps, CCKWs, Motorbikes, Landrovers, FV432s, and some ex Warsaw Pact Russian stuff. On a personal note when I last took the truck out it didn't warm up at all, so, suspecting a problem with the Thermostat, I bought a replacement one this last week along with a new top hose. Attempting to fit it this weekend, I discovered why the truck has been running cold in this cold weather.... there was no Thermostat fitted !!! :( The question gentlemen, is why....? Currently seeking advise from those in the know on the HMV Forum, as the new thermostat doesn't seem to fit very well, and I don't want to bolt the Thermostat Bell Housing down until I've sussed things out.