I can't find 3/16 line separators anywhere, so I 3D modeled this guy. It's not going to be cheap for them to be fabricated, but might be worth it if I can make the financials work to produce a bunch and try to recoup some costs.
Left hole is recessed for a Hex Cap Screw, Right hole is tapped 4-48.
3x .188" half-holes. Two pieces get screwed together to make the separator.
I'm slightly concerned about getting to the underside to tighten the "other" screw. I'm trying to keep the cost down by making a bunch of a single part that are interchangeable.