Response from Jonathan: Grant,
 
The picture probably is distorted because your arcade cabinet has a medium resolution monitor inside of it. While most arcade games use standard resolution monitors (15 kHz), NFL Blitz and many other 3D arcade games use medium resolution monitors (25 kHz). These monitors have a higher refresh rate and resolution which allows for better animation among other things. Unfortunately if you try to install an arcade board that outputs standard resolution in a cabinet that has a medium resolution monitor in it, you will get the symptoms you are describing. I know there are some video converters that will convert both standard and medium resolution to VGA (computer) resolution but I don’t think there is one that takes the signal from standard to medium.
 
I also have a theory on why your joysticks are not working. Dedicated NFL Blitz cabinets as well as some kits used 49-way joysticks instead of the standard 8-way joysticks. Of course, 49-way joysticks give you better control of the action but also require the use of a separate breakout board and harness. Since they require this separate board and harness, they are not wired like standard joysticks through the JAMMA harness which maybe why they are not responding. Keep in mind that this is just a theory and you’ll need to check your wiring against the standard JAMMA pinouts to see if this hypothesis is correct.
 
Hope that helps. Thank you for your questions and good luck with your project.