To add here,

I installed icentropys' eyoyo bnc\multi monitor on my 98 4020 last night. used a stainless plate to cover the hole, and flat mounted it to that. Works PERFECT.
Letters are bigger and much more defined compared to burn burned in wiggly CRT.
While I was at it, I hooked up a chromecast to the hdmi port

Now I can switch between the ball game and machine info at the touch of a button. Noice