Yeah be sure you have the constructor module still in the design. Gadzooks! You might need to strip an engine off your previous design as they are rather "heavy" in construction cost. But that's as it should be.

One further notice to you that I can mention. Don't set up a fresh starbase without at least 3-4 constructors in the initial start up. Single startup Starbases with no protection are eaten alive by the AI at the start of your 1st war. So that Morale base of yours with 4 mining and no defenses is history no matter how far away it is from your border.

If I find a natural resource base I want to keep or "liberate" one, I will at this point "glue" it down for my race with reluctantly one Constructor, then augument it with 3-4 Constructors ASAP.

Hope this helps.

There's an option to "strip functional components on upgrade". It is checked by default. It's convenient, but makes it easy to forget things (like constructor modules). You can uncheck that option or just remember to add everything.

Can anyone out there confirm that they've seen a fully augumented starbase survive a 43+ logistics fleet attack?

Once, but I think it was luck. The next fleet had no trouble with it, at any rate.

Still, pimped-out starbases are a good speed bump. If nothing else, they distract the larger fleets of the enemy--a weaker starbase could be killed by only a couple of ships, but a big starbase needs a whole fleet, and that fleet won't come out in good shape.