Sorry to hear about your experience with this company. I was interested in their 43" cabinet as well, mainly due to the fact they have free shipping and it can be flatpacked and quickly assembled with camlocks (and idea that may sound better than it actually works in reality - Ikea furniture is not meant to be constantly nudged, lol).
Then once I found out about the limitations of the design, as you indicate, there is no way to access the cabinet from top. The monitor and playfield glass (plexi) are fixed in place and not designed to be removed unless you take the cabinet sides off. Puzzling design choice there when it could have easily been avoided with a more standard playfield glass design.
Anyway, I've opted for another vendor you didn't mention, "Monster Arcades" out of Carrolton Georgia (West of Atlanta).
Made the choice primarily because they have a WPC styled cabinet but also they are within driving distance from me so I don't incur shipping fees. The one thing about their cabinet though (they offer 40" standard and 43" widebody available in both unfinished birch and in thermal laminated birch), is that they have reduced the depth of the cabinet from standard WPC of 51.5 down to 47 inches. This makes the playfield area more suitable to a 16:9 format monitor/tv but at the expense of having to use non standard siderails, glass guards and playfield glass. The monitor actually may go under the backbox slightly, which is actually just like modern machines from Stern and Williams and gives more of a 3D effect, in my opinion, than when the cabinet is longer than the monitor and you have to use a wedge spacer there. FWIW, here are a few shots of modern Stern cabinets at the back:
FWIW, that's a quick summary if anyone is considering options. Virtuapin.net has one of the only available WPC widebody cabinets that is exact replica of the late 90's WPC machines. I couldn't afford the shipping from Michigan though and opted to source one closer to home.