I was just stating the official reply from Seiko. I don't know how come your source from Seiko is different as mine said this is the official answer since they find no sales record and most importantly, no manufacture record. Even if they do it for internal use, there will be a manufacture record.
To answer your 'questions', carved dial is indeed rare and fragile to make. These are the earlier generation and one can imagine some of these watches were in very bad condition. Grand Seiko was never that popular 5-10 years ago, let alone 15-20 years ago. So to 'dissect' various pieces and put together one good watch is not that difficult or costly. Even right now a good condition YG 3180 cost only around $2k+, given that GS3180 is pretty sought after. As for the medallion, if it's done by Seiko, why the need to create a unique one when their Platinum model use the ordinary medallion? I would think to make these are not that difficult if you come with your own design, compared to making one similar to the original which one can compare. I do believe the lion in both medallion is different too. Why is there a difference? Anyway such discourse is commonly found in Omega thread and it happens that such 'redial' and 'franken' watches were pretty common during those period.
To me it doesn't matter what the answer is but the information is very interesting and educational. We can always agree to disagree. Just note that it is not what I say, I'm just a messenger, sharing what I heard from Seiko.