I've never been able to successfully use the search program since the changeover myself. I get the same results as you. I try "Model 66" , I try Model #66", .. and get threads that never mention the Model 66. In fact, at the top of the results page, it indicates the search is for "Model" or "66" - not "Model 66", which was what I typed in. I've never seen a satisfactory explanation of why some of us don't get the results advertised in the Forum directions.
Despite the many advantages of the new Forum format, I could actually USE the search function on the old one.
I would ask the mods for some further instruction for those of us with this technical deficiency.
Regards,
Jerry