Chewtobacca said:
I had only four damaged files, and the rest were fine.)

So if I've understood correctly, in your case repair wasn't required-- only verify and unrar.
I do believe the original par set is b0rken.

As althor kindly supplied more redundancy than I needed, I reinstated those four damaged files giving me 44.
Then repaired the lot using the new par set. In like Flynn!

Forty or more incompletes is a lot, no doubt.
Though I suspect hiccups from my Internet service provider to blame, not the news service provider.
(A month from now I'll have new ISP so no worries.)
With diligent redownloading of parts I might've reduced the forty considerably.
Nevertheless if NSP has even one incomplete part it would've been unrepairable
if the par set was bad, if my theory is correct.

That new par set should be posted for posterity methinks.
To show my gratitude I'd volunteer to do it; however, my ISP seems flaky
and probably best posted under althor's name anyway.
Then some posterior who's not following this thread might have better odds finding it.

Thanks to Chew and Mattman for your suggestions.
Hugs and kisses for althor!