For some reason I was thinking back on some muppet characters and two of them stood out as being similar to a couple members of your cast, or to say that someone on your team could play them well.
One was Dr. Bunsen Honeydew the scientist:
who could be played well by Matt, mostly thanks to the round head and glasses.
And to go with Dr. Honeydew, you need his assistant Beaker:
who due to his height, red hair, and being quite slender, could be played by Bill.
I cannot think of a whole video using these two, even though it may be a way to revive the Loading Ready Labs, I was thinking of giving them a bit part.
Lets say Paul in a video needs some sort of drink concoction made up, he could go visit Dr. Honeydew (Matt) and tells him what he needs.
Dr. Honeydew: "No problem, could you grab me the [insert ingredient here] from the cabinet?" as he gestures to Beaker (Bill)
Dr. Honeydew and Paul chat while he works, then Beaker comes back over with the ingredient and gives it to Dr. Honeydew.
Dr. Honeydew: "Ahh, thank you Beaker."
Beaker: "Meep."
It'd be nothing more than a five second reference, but those are often the best kind.