Would anyone be willing to give me a couple minutes of help with a circuit?

[The Lightning Stalker]

Sometimes you can find an older scratch-and-dent Fluke benchtop multimeter on eBay that can do 5-6
digits. I picked up a 5.1 digit Fluke for $80 a couple months ago that has a missing rear bezel, which
bothers me, but it works and is what I could afford.