If no one already has the measurements, it's pretty simple to do yourself. Grab a few (4-5) with consistent, straight lines (where the zero line is lined up too). Then measure one unit on all of them with your calipers and then use the average to calculate the measurement for your units (so the average measurement you get for 1u, when divided by 4 is the measurement for 0.25u). Have you see the Caliper post?
https://www.felinediabetes.com/FDMB/threads/dosing-with-calipers-updated-w-videos.79851/
Also, as an alternative to measuring 1u, I've heard some people measure 10u because it's bigger and easier to see

when you get your average for 10u, you can divide by 10 to get 1u then divide the 1u measurement by 4 to get to 0.25u.
Hope that helps

Good luck on your switch