Is this a police or military holster?

[lugerholsterrepair]

JD, Unlike pistols, it only improves a holster to repair and stablize it's deterioration." If it is done Correctly" A number of people often ask if it devalues a holster to have it repaired and I have to say, what good is it in parts and pieces? There are many types of collectors, those who only want the best original, those who dont care if it has a little honest wear or battle damage and those who will accept repro's made in Pakistan. There are also many in between.
I think it is up to you to decide if the added strap and D ring is acceptable to your collecting desires. If it were mine I wouldn't like it, particularly because I don't think it was added before about 1970. I also wouldn't be excited about removing it as it would leave some unexplained holes in the back. Kind of a cunumdrum, damned if you do, damned if you don't.
If the stitching is not too bad and you will use the holster for display only I would leave it alone. If you monkey around with it and use the wrong thread it could damage it further. When repairing these it is important to use the proper type of thread, color thread , thickness of thread and the proper tie-offs on the inside. If you do it poorly it is best not to do it at all. Not to say you would do it poorly but as you can see, some thought must go into it before you start.
Restoring a German Luger holster can be as simple as stitching here or there or re stitching every thread in the holster. Replacing many of the small parts. Replacing the metal hand hammered studs. Moulding a front body and replacing it. Taking a body off another holster and putting it on the repair holster. Same with the top. Replacing tops or in the case of an Artillery, replacing tool rod pouches or ears. If any of this is done correctly it is very hard to detect. If done correctly it vastly improves the value of the holster.
As far as thread goes, linen (flax) Thread is difficult to locate and expensive. If you think you need a piece to stitch up your holster belt loop let me know and I will send you a yard of it.

Remember, it is difficult to stitch up a belt loop...the top ones are directly under themselves and a needle will butt against the strap, making it hard if not impossible to stitch the top without removing the bottom first. The bottom is difficult because it is way down there and the right strap is too close to the side of the body to get at . All the old thread must be removed before starting as it is in the way and will look like hell unless it's gone. This is usually about half the job! Good Luck! Hope this answers your question. Jerry Burney