Submit it somewhere else and perhaps ask for conservation service evaluation. You're probably better at identifying lacquer than me though. I couldn't tell at all. Similar to yours, less than 200 of this variety (Canada 1947 50c Maple Leaf curved right 7) were struck for both circulation and specimens. Before and after pics below. See that squiggle next to ET? (expand the pic) Under a microscope there was a bristle looking thing in the squiggle. I was convinced it was retained strike-through of bits of brush they used to polish the die. Also note the tiny pits in the fields. All that stuff was in the lacquer, and probably some "hairlines" in it from when the lacquer was applied. Now it's all gone. Just an example of how PCGS screws up I guess.
Yes, thanks for that bit. I sound like an ignorant whiner but think I am not. Also, without revealing too much I have sent coins back that were completely wrongly graded and they came back with a grade 5 points higher. BTW, nice coin there Sir!
Is it possible they are interpreting the darker area to the right of the 5, and to a lesser extent above it, as rubbing from cleaning? Still, I think they got it wrong. Nice coin!
Meanwhile, this got a PL(proof like)67 with the corrosion spot AND a post-submission fingerprint treatment....This coin I thought would get a "Details" but did not...
First set is a proof set, the second set is the specimen set from which it came. The 5 dollar also has verdigris at the 1 o'clock position.