NMK939 Fifty-Eight SKX007/SPRD Watch Case Bundle: Gold Finish



Once considered a "Poor Man's Rolex", Tudor has really come into its own in recent times. This NMK939 Fifty-Eight SKX007/SPRD Watch Case Bundle in Gold Finish pays homage to the eternal crowd favourites BB58, a vintage styled diver complete with details such as an ultra slim low profile bezel, top hat sapphire crystal and option for an Oyster Rivet bracelet. The best part is, everything is pre-assembled, making this the perfect plug-and-play dive case. Check out our Fifty-Eight collection for more part ideas!

NMK939 Fifty-Eight SKX007/SPRD Watch Case Bundle: Gold Finish

Case Specifications:
Case Diameter: 39mm
Lug to Lug: 47.5mm
Thickness: 9.5mm (Case only)
Total thickness: 13.5mm (Case with crystal and slim caseback)
Lug Width: 20mm

What's Included?
- Top Hat Sapphire Crystal (Clear AR)
- Ultra-Slim Line Coin Edge Bezel for Sloped Bezel Inserts
- Integrated Brushed Chapter Ring (Rehaut)
- Brushed Oyster Rivet Bracelet (Option)
- Matching Sterile Crown

- Caseback Gasket
- Pair of 20mm Springbars

Parts Compatibility:
Fits all SKX007 Sloped Bezel Inserts, SKX007 Crowns, and SKX casebacks and is compatible with all our existing dials and hands. 

Compatible with NH35/36/70/71 etc and NH34 movements for GMT builds.

Customer Reviews

Based on 10 reviews
NMK939 Fifty-Eight Bracelet Clasp Mod

I love this GMT build! Made it for a dive trip to Australia and wore it on multiple Scuba dives to 20m and Free dives to 50m, as well as in super heavy surf. I used a flatter 200m caseback that I had in my parts bin as the Namoki one is a bit bulky - (in case you're wondering if other SKX parts will fit).
One nag that you'll need to attend to (if you're fussy) - The clasp needs modding to get it to fit flush with the bracelet. It's damn annoying having it sit up so high as it catches on everything. This is not a function of small wrist size - I have a pretty standard, 7 1/4 inch wrist - the clasp sits high even when the bracelet is laid flat on the bench. The issue is with the shoulders on the clasp under the lifting tongue that need to be removed to get it to sit flush.
It's an easy Mod. Just file off the 'shoulders' under the tongue on the clasp so it can sit lower, then bend the tongue down - it's a straight bit of metal that hasn't been curved to fit. Protect the tongue with tape on the clasp and grip it with something long - I used an adjustable wrench - then gently bend down to your liking. You can see the before and after in the pics. I didn't get it quite perfect, but it looks like it's supposed to now and doesn't catch on anything.

Jason C. (Chula Vista, US)
Nearly perfect

Love this case! I have a BB58, and this is almost identical. The finishing is very good. Not Tudor good, but that's not a fair fight. It's good. I've built 2 watches off this case and both look great.

What could be better about the case? The lugs. They copied the Tudor lugs perfectly. Except for the spring bar placement. So, aftermarket Tudor bracelets will not fit. An SKX013 bracelet also will not fit. Again, different spring bar placement. The only bracelet you can put on this case currently is the one you have to buy bundled with the case. I really wish they had designed the lugs to fit an existing bracelet option and offered the riveted bracelet also. The difference in shape would have been un-noticeable.

The bracelet... (I'll review this here because you can't buy it separately). The bracelet is very nice as well. The finish is just as good as on the case. But it has one major flaw... the rivet that holds the last link to the end link binds on the end of the lugs. Like that hole is 0.1mm too close to the lug. You can even see it touching in the product photo.

Despite my bitching, I love this case. I'll probably buy another one to build a watch for a friend. I just wish I could put it on a bracelet.

Watch M.B.I. (Dublin, IE)
Almost perfect BB58 homage

I really like the size of this case, the top hat sapphire and the character of the lines. Perfect for a BB58 build or a mid-century tribute.

Lawrence P. (Gillingham, GB)
Better than the original

Great kit to build your homage to the BB58. With a good range of dials and hands you can build the Watch to your desired specifications.


After many case purchases, this is by far my favorite case, from the day of the build I have yet to take it off. Very nice.