Thanks again Bryanna!
The guy in the dental lab place that I saw is a "Dental Prosthetist". Is that the same as "Prosthodontist"? Anyway, just now I found more about him from the internet (after I saw him in person!) and looks like he is well known here (or at least that is what his web page seem to suggest).

Anyway, I think he might have said that he usually takes the impression twice (??), not sure. Pity I didn't know much about it, so could not ask about the wax model. I guess if I go through "my" dentist and if I'm not happy with the new denture (or modified old one), I could always go back to him (minus the double cost!). I will see what happens with my tooth at the dentist's and I guess will make the decision later on. This dental lab guy already told me that he would not add a tooth to my current denture, it is too thin and he doesn't like it. My denture does not even have any clasps on the sides any more, and it still sits! It is very handy for taking it on/off quickly and with one hand. I am very very worried about the side clasps because I remember how they mercilessly pressed my other teeth and I did not like the feeling of metal scraping along my "good" teeth every time I take it on/off. But this guy is adamant to use them again and said that he does not like or suggest flexible dentures. Some time after that, I heard about Dentiflex flexibles (can't find it now!! maybe I spelt it wrong). Not sure if that avenue is worth exploring??