The "universal" replacement monitor chassis out there are for the most part STANDARD resolution (a.k.a. "CGA" ). That means they can only be used to replace an original monitor chassis that was standard resolution.
The Wells-Gardner model U2000 is standard resolution.
Neotec manufactures monitor models in several resolutions. Exact model number of the original chassis is important.
Remember, that these universal replacement monitor chassis are designed for certain specifications. In particular the yoke impedance and the picture tube neck diameter.
Also, since the time that article was written, 8liners.com (a.k.a. genao.com and Atlas Amusement) no longer sells the Jen Shinn brand replacement chassis. They now sell only the Wei-ya (a.k.a. Huai Electronics) brand line of replacement chassis.
http://www.8liners.com/datatech/monitor.html