While not being a keeper shot, it serves the purpose to try out an adaptation of bellows into a Focus Rail. Advantage being small increments can be easier, bonus is bellows do what they do, allow greater magnification, closer focus
After purchase of bellows, cost = $0.00 + a lot of time and effort to drill and tap all those holes. All parts either Gathered, or permanently Borrowed.
If there is ONE constant that I love in the Photography world, EVERY camera maker/Accessory maker has the exact same stud/thread combo, on tripods and camera bases. 1/4-20 UNC [unless you go pro with 3/8th, even then an adaptor insert brings it back to standard] thus one can make things as such in a home workshop
rather easily.
Until Next time
out there in The Great Beyond.