While attempting to repair a problem with a clients self installed Lync FE IIS services I came to the conclusion that the Web Components Services was broken. No problem, right?
Simply uninstall the Web Components and then re-run the Deployment Wizard. I did that and returned to IIS to see MCX now missing. Suppose I should have expected that. No problem (again), I’ll just run the MCXStandalone.msi…
So the .msi says that the MCX is still installed, did a remove and ran it again to re-install. Done.

Checked IIS and MCX has returned, only problem is it still doesn’t work when I run the www.testocsconnectivity.com test.

So what’s the issue?
For one thing, the Environment had been installed and updated to CU6 but the MCXStandalone was still on the relative CU4. The MCX Update was found here

Secodly I assumed that the MCX listening ports were still defined as you usually cant install the MCX if they aren,t. Better safe than sorry, so I re-ran them too

Set-CsWebServer -Identity -McxSipPrimaryListeningPort 5086
Set-CsWebServer –Identity  -McxSipExternalListeningPort 5087

I restarted all the services for good measure, probably wasn’t necessary.

And voila!