I agree. Sturm, and others, have tried all kinds of horrible ways to take stuff they can't sell "as is" and get them sold in a modified format. Popular mutilations I've seen:
1. Vests - rip the sleeves off
2. Shorts - cut off the lower legs below the knees
3. Over dye - recolor the item to make it look "kOoL" or less military
4. Shoulder bags - take a small pack or breadbag and sew a shoulder strap to it
Various items that I've seen over the years...
BGS Sumpftarn jackets turned into vests (one on eBay right now, in fact)
Shorts made from British S94 and Swiss TAZ82 trousers
Belgian M58 Jigsaw trousers dyed black, German Polizei riding breaches dyed black
Israeli and 1970s/80d German BW "shoulder bags". Also seen these over dyed as well
Things to look for to identify these items:
1. Remember that if it looks odd to concentrate on whatever it is that has your spidey senses tingling

2. Look for stitching that doesn't match color and/or style of the rest of the garment. Sometimes stitching of over-dyed items retains its original color, which means something like green thread on a black item. That's obviously not original.
3. Look for the tags/stamps. If the tags are dyed then that tells you a lot right there. If the tags are altered or added, that also tells you to be suspicious since nobody messes with tags almost as a rule (Sturm is an exception sometimes) because it's not worth the money.
4. Sloppy work. I have a pair of British DPM shorts where the legs were very roughly cut off and a single stitch hem was added. This means the ragged edge of the cut cloth is exposed and prone to fraying. No way would any real military garment have such crappy work, but a company trying to turn a liability of too much of something into a profit would definitely do something like that.
Now, have said that...
I've seen some things which might look to be like commercial modifications but were in fact done by military contractors for the military. You don't want to confuse legit military modifications with commercial butchering. However, these modifications tend to be quite involved and professionally done to achieve a purpose not likely attractive to the consumer market. Some examples:
1. Epaulettes added to KAZ57 Austrian dot camo jackets. Originals didn't have them, so they were retrofitted on when they changed to shoulder rank the year after initial production.
2. Turkish officers have shoulder rank, but nearly none of the types of stock uniforms have epaulettes. Therefore, epaulettes are sewn in usually by hand with scrap material. They look like Hell

3. Swedish m39 uniforms made in the 1930s, 1940s, and early 1950s were retrofitted to have the same features as those of the ... damn, I forget the designation! (M50 something or other). This meant adding pockets to the legs, leggings, to the cuffs, and two rear pockets to the tunics. You can tell this by the different color of the wool and evidence of original seams being ripped and restitched.
4. Czech reversible oversuits converted into simplified sets designed for wear of one coloration only. This was done to breath new life into very used up originals. Commonly called "reissues".
Just some passing advice

Steve