I will see what i can do as well i have close links with UK, Japan and US.
Just noticed looks around 6mm 50 to 55 yards and i and many others could quite hapilly live with that. Was led to believe they were larger though.
Kept using as a preference the standard supplied Tasco wheel (approx 60mm) over 16 years ago, gaps 3mm 50 to 55 with only those marks could split up within a foot, ask Calps. 4" wheel refocussed to 70 yards total range 10 yards to 55 is 162mm, just had a look.
Half way is 52 1/2 yards, 1/4 way between 51 1/4 yards, not good enough? 1 1/4 yards is 45" (1.14M) Errors will be the same regardless of the spacing.
If you can repetitively range a target within 1 yard or better i would leave as is. The point trying to make having no actual marks after 50 until 55 you will have to take a dfferent approach, just visualise its easy.
It would be interesting what the Hungarian chaps marking are.