The ability to jury-rig ruined Rings would be pretty nice. perhaps there would be a (pretty sizable) penalty to its habitability?

I did not played a proper game with this mod, but judging from screenshots the cost of jury-rigging + complete restoration after repair = complete restoration from the ruined state.
I think after repair restoration should cost slightly more and take slightly more time to do then it is now (but less then restoring from scratch).

From gameplay perspective player will get to choose - "Do I want additional income now" or "Do I want to save time/resources later". Player than have to consider - how far "Mega-Engineering" tech is, what economic situation e.t.c. witch give gameplay more depth while not increasing complexity

And from roleplay perspective it make sense as well. Let's say your scouts stumble upon a ruins of ancient Dyson Sphere.
After some research on site your engineers make plan on basic repear. While scientists have no idea how to make new solar panels as sturdy and efficient as original ones you totally can use existing to generate some energy. The only problem is power relay system - it's practically non existent. The plan is to connect all working sections of solar panels with array of power beams and put previously wasted energy to good use.
A few decades pass, your empire is bigger and stronger then ever. But with scale and technology raised the hunger for power. Your engineers looked at old, semi ruined Dyson Sphere which their ancestors turned on long time ago. The possibility to increase power output of the station up to tenfold is surely pleasing, but it comes with a challenge - the messy power relay system is not only gravely inefficient but totally unscaleable. To implement better solutions you need to tear it down with, unfortunately, some of costly structural elements.

As for numbers for restoration I would suggest half of the difference between current cost and full price. For example for Dyson Sphere from 36kM and 4.2kT to 38kM and 4.5kT
The cost of Jury-Rigging itself (at least on paper) looks fine to me - not cheap but quite affordable for an early game

@Wincent I kinda agree, will probably make that change for the next update.

@Nuranon
I've tried to find alternative word for "Jury-Rigged" in Russian, but there were no terms with the same meaning. From my point, "Частично завершенный" suits really well (translated as "partly comleted"). Together with my friends we use this term, because it is easy to understand what we are talking about.

So this the list:

• Частично завершенная сфера Дайсона (Jury-Rigged Dyson Dphere)
  
• Частично завершенный научный комплекс (Jury-Rigged Science Nexus)
  
• Частично завершенный дозорный комплекс (Jury-Rigged Sentry Array)
  
• Частично завершенный стратегический координационный центр (Jury-Rigged Strategic Coordination Center)
  
  Hope this will help. I'll try to translate all discriptions today after work..
  
  P.S. Thanks for your awesome mod! It really helps in early stages.

Thanks a ton!

Don't make yourself crazy writing descriptions, I have myself spend way too much time spend on that ;)

The Names are now added.

There now is a full Russian localization (part of another mod) if you are still interested, see Description.

How about Jury-RiggedRingworlds? So finding one doesn't require megastructures tech, but only nets you a ~20 district section with ~80% habitability. Once you unlock Megastructures tech, you can "terraform" the ringworld into a vanilla one.

Would be nice to get use of an early Cybrex Alpha...

@akeean see my response in the main comments - basically: I had started working on it early this year but eventually gave up because it was too complex and because I moved on to do other things for a while. Might return once the announced Ringworld changes happened.