ZF4 Repro Focusing Issue

So I've searched all around the internet and this forum and haven't found any posts related to my question. I have recently purchased an all matching, all original K43 AC45 in excellent condition. It did come with a reproduction mount and ZF4 Scope. This is fine for now until I am able to purchase an original one to match the rifle (also would rather shoot with reproduction than run the risk of damaging an original).

Upon inspection of the reproduction ZF4, I have noticed that the focus is significantly off. It allows for excellent focus at a distance of ~5meters to ~15meters, however after 25meters it is very blurry; worsening with further distance. I have tried adjusting the elevation knob; cleaned the front and rear glass lenses without any luck. It's not my eyes as I have several other 4x fixed scopes which allow for clear focus at distances 10m to infinity. There are no rattling noises or apparent loose parts. Any suggestions? Do I need to bite the bullet and purchase another ZF4? Does any do repairs for these?

Input/advise greatly appreciated.

With the exception of the windage lens, the ZF4 is a fixed optics scope. There are internal provisions, though, for adjusting the focal distance of the front and rear lens pairs. Threaded shrouds containing smaller lenses screw onto the large lenses and are secured in place with set screws. By turning the shrouds relative to the large lenses, focal distance for each pair of lenses can be adjusted. Afterwards, the shrouds need to be secured with the set screws again.

This is not a job for the faint of heart as you not only have to remove the tiny screws preventing the lock rings from becoming accidentally unscrewed, you will also need a special tool for removing these screw-in rings.

https://www.milsurps.com/showthread.php?t=54108

Thanks. Yeah so I did a bunch of research on the issue/topic. Sometimes the parallax can be off on non-adjustable magnified scopes however they usually have a means to adjusting the distance between the front and rear lens to obtain a proper parallax. More modern scopes have this as an adjustable option, usually on the front objective or as a tertiary knob on high end models. At any rate I don't have the special tool.

I sent out an email to Don Miller, at optikhaus@yahoo.com but I haven't heard back.
Does anyone know of any other optic repair companies or individuals?