I'd love to have the set in a giant NGC multi coin holder, but I don't want to invest another $200 in them, lol.
Just a guess... but grading each coin will be what... $15 a piece, times 9 coins plus the holder, plus $26 shipping. It would be a lot.
I can't say I'm all that happy about their situation, looking at your pics. PVC doesn't always manifest as green - early-stage stuff is more milky in color, resembling a "haze" more than specific spots. Green comes later. I see some of that in your images, understanding it *could* just be the images since I'm most worried by the lowest coins. The Thruppence looks fine (aside what I see under the EE's in THREE, which could be just a scrape on the plastic). In your shoes I'm seeking out dealer-experts on the issue, to see if you have viable options for conserving the pieces while not losing their cachet as an original set.