I need some more hints to understand the improvement, although its generally good to re-build it considering the sad state of the assembly/installation that you found.
I see that the current design brings the 11 MHz signal to -2 dBm before intering the first ZHL-2+, but since that has a NF of 9 dB, that seems to only degrade the phase noise to -2 - (-174 +9) = -163 dBc. That seems OK since we only need -160 dBc from this system. Probably the AM noise is worse than this already (we should remember to hook up a simple AM stabilizer in 2016, as well as the ISS).
What else are the main features of this improvement? I can reward a good summary with some Wagonga.