Another thought would be hook the two compressors up in tandem, that way you would be getting the value of the CFM output from both compressors and the added 25 gallons won't hurt. I don't know the CFM output from the compressor that has the 25 gallon capacity but often a larger tank means they put a bigger compressor head on it. Your still in the over use mode but, if they where working together your recovery time would be much better.
Make sure you rough up the metal on the new pieces you put in with something like 80 grit paper on a DA...that way you'l get much better mechanical adhesion.
The installation of the new parts looks quite well done...good job.
Now if I had know it wasn't an American muscle car well...it wouldn't have mattered...LOL