Previously, I stated that I did research on what type of DMM is best and the best value. I knew the 8840a was going to be the cheapest and it is widely common with hobbyists. But in my search, I noticed there wasn't many documented cases where someone had replaced the VFD with an aftermarket display. I did find one forum post where a user had implemented some LED 7 segment displays and a few LED bar modules. But he had a Fluke 45 and not a 8840/8842 where I could have just used his research. But not all is lost. The 45 has a VFD and basically is the same except for the display driver IC, D7527ACU. The 8840a uses the TMP82C79P IC and a couple of NE594D, which is a VFD driver IC.
At this time, I know that my VFD is dead and I have checked all voltages and they are spot on, so I am now planning on hacking in some 7 segment displays in the place of the VFD. I do have a 4 digit 1.58" Common Anode display and 3x 14mm x 40mm Common Anode displays to start playing with. In other hackers documentation, they are using common cathode displays. So I may order some CC displays just to make my life easier.