Seiko after market case quality?

[mountaineer]

I am planning out a build using an after market Seiko dive watch case.

Water resistance is important (will not be actually diving but pool/snorkeling/etc).

Is there a difference in quality between after market case sellers, ex.// Namoki,Crystal Times, Tokilab ?

I am looking at a 42mm. MM300 style case with screw case back.

Thanks for any insight

[hako]

In the past, I bought cases from Namoki and Tokeilab.
Both have excellent build quality and tolerances.
They come with proper crystal and CB gaskets.
They even had the protruding crown tube that allows to align stem and movement perfectly, so that the dial is aligned automatically as well (on the flip side you have to take a bit care when inserting movement and dial not to search the dial)

As for WR, I can not make a statement, because I have no testing equipment.

[Aikidosan]

I've had several Proxima monoblock MM300's and build quality is excellent. They've all been in the ocean without issues. Fantastic bang for the buck.

[mountaineer]

@hako @Aikidosan

I appreciate the insight. Those were the answers I was hoping for.

In the meantime, I found a used mm200 build with oem, dial, hands and lume pip. It was a fair price. I purchased it.

We will see how it looks in person.

[hako]

Careful if you think of buying a Proxima and the start modding them. The dial will fit but the rest ist not compatible with SKX modding parts. In particular the holder for the chapter ring and hence chapter ring geometry ist different. Guess how I know ...
Apart from that, I can only second that the Proxima does have an excellent build quality.

[big eebee]

I have used all of the above and crystal times. On the proxima mm300 you only really need to change the dial. So best for a mm300 build . As for skx type builds, crystal times edge it for me. They did a ltd skx version with hev. This was a very nice case

[mountaineer]

@big eebee @hako was it hard to remove the parts on the Proxima MM300? I have never work on a front load case. Is it easy to damage parts/gaskets/etc.. to get access and replace the dial?

[hako]

Not hard, but you need a Jaxa-tool.
Remove bezel with a case back opener (put some tape on the blade to protect the surfaces)
Screw open the crystal holder. I can't remember whether the threading was left-handed. Do you, @big eebee ?
Lift off chapter ring and hands and then you can replace the dial.
I did all without removing the movement.
If you want to remove the movement you will need an Allen key to unscrew the crown-stem coupling part.

[big eebee]

It's super easy. Remove , bezel and click spring. You do need a jaxa. I clamp the watch head in a movement holder. Helps stop slippage. You turn inner case clockwise to undo. Anti clockwise to tighten. No need to remove the movement
Just remove hands. Seiko dials feet fit into the plastic movement holder so dial will lever off easily with a flat blade
Now install new dial and work backwards
Good luck

[big eebee]

Some new proxima's have removable mid case. These are held on by screws. More than one version. On one screws are under bezel. The other screws are between lugs
You can actually change your mm300 to a turtle midcase. Cool but unnecessary