I don’t know the answer to this but, are there metric cutters offered in the world of checkering? I ask because 17 lpi equates to a pitch of 1.5mm (ie: 1/17 = .0588) (1.5 x .03937 = .059).

Custom cutters aside, I’d imagine that, if metric cutters are/were used in parts of Europe around the turn of the century, they’d certainly have made their way into the toolboxes of individuals tasked with checkering back in the day. And now, today, if metric standards are available, a “17 lpi” cutter may very well be available off the shelf.

If you gentlemen are serious I'll see about getting 17lpi cutters made.

Pretty simple to make a tool that'll hold these + a little tuning-up (grinding) to get the rakes/reliefs ground properly for wood, but here's an option for 17 lpi spacing, provided a 60º included angle is okay.

https://www.mscdirect.com/product/details/03929197

Recently I recut a VH that was courser than 16. It was around 14-15.

To me it does not matter much, one can cut new checkering using modern standard spacing intervals and have the work look correct. Since there was a lot of variation from gun to gun originally anyway.

Most of the power checkering tools out there are fully adjustable for spacing, so odd and custom spacing can be had. If you like working with power tools. I do not.

The old J&E company offered one handle with spring loaded spacer blades that would just attach on allowing multiple spacing settings to be had with one handle and cutter. But they were set intervals.
I am sure an adjustable setup could be made for a hand cutter, but I could see it being expensive, but if it worked well, I would certainly buy one.

Ullman Precision bought out J&E when they went under which is what got them going in the business, but they do not offer that adjustable handle in their product offering.