Looks good. I just built a DIY probe holder, and its working great. I did just like John said using a 1/2in JG fitting. I didnt have to drill the backside out. I had seen people doing that, and on 1 I had I did do it, but I bought another one, and it wasnt ness. I dont know if it was a different brand, but it went in fine. I wasnt able to get it out once in, so make sure you are ready to install it.
I used a 3/4in T, and installed reducers to put the 3/8-1/4in hose, and 3/8-1/2in for the probe. It took about 5min to make, and cost about $10. Its been running for 3wks, and working perfect.
Derek