Some things to look for if you find a hollow mid-link 93150 and want it to appear 'genuine' at a short distance:
1...Make sure the removable links have screws that pass all the way through the links...not blind on the threaded end. If the screws are too short, try to find screws that are flush with the link on the threaded side with the same brushed finish as the links.
I had a pretty good 93150 with blind screws in the removable links, so I drilled them all the way through, put the screws back in, and pressed short pieces of stainless rods in the holes. It took 2 or 3 hours but they are still in place a year later and look a lot better.
ST has good replacement hollow mid links but they have gone up in price quite a bit.
2...See if the clasp has a rivet where the clasp cap connects to the 'Z' clasp on the flip-lock end. Many replicas have spring bars. You can replace the spring bar with a rivet but the flip lock may not pass by the rivet heads. Catch 22.
3...See if the Z clasp has an 18 at the end of the reference number. '18' = 18 karat. Look for Z blades without the 18 (unless you have a tutone watch.
4...Try to find old type hoods (end pieces) without cut-outs for removing spring bars if yours have the cut-outs.
If the hoods have tubes soldered in them and the spring bars do not line up with holes in the case...you may have to bend a slight curve in the spring bars...assuming the tubes are made to accept 2mm spring bar tubes, not 1.8mm.
If the tubes are made for 1.8mm bars, you can cut the tubes in the center to allow them to expand...if they do not break off. The solder bond is usually not very strong.
5...Older genuine bracelets have the Z clasp hinge pin just pressed in and held by friction. Many replicas have small tabs bent over the pins to keep them in place. No one notices but if you swap out the Z clasp for one without the 18K mark etc. look for one with the old type of hinge pin setup.
6...If your watch is an older vintage model, try to find a clasp cap with the indentations to hold the bracelet under the cap. I made a 'crimping tool' out of strap notching pliers but it was a hassle. Probably not worth the trouble to a sane person. Ha!
7...Typos are free.
