The 22.5" WSM thermometer has a 2.25" dial face, and most replacements seem to be 2" or 2.5" or 3".
My advice would be to discard the bezel, enlarge the stock hole to 3/4" using a 3/4" metal hole saw and install a Tel-Tru BQ300 with 2.5" stem and installation kit. Looks real sharp.
You can see an example with photos at the top of this page: https://virtualweberbullet.com/installing-thermometer.html
You'll be hard pressed to find a better stem thermometer than a Tel-Tru.
Surprised nobody has replied. I have been wondering what people would suggest.
I was in Westlake hardware today and saw one of these for almost 25 bucks.
My next door neighbor has the same one on his drum smoker. He smokes way more meat than I do.
If I needed a thermometer I would probably give it a try.