Going back to MARIO Mew. This are a few images from different sources (most of them are from Twitter).
Just sharing this because in the future years we can acknowledge a part of the range of the Mews that were distributed.
51259 is the lowest ID I've seen. (Sold on ebay I think) Followed by 51273 (which is the one of this post) 51292 (From Imgur, and the one of the letter from this post) and 51295 is the highest seen yet. (From Twitter).
According to this distribution, 151 Mews were distributed. For sure some of them were between 51259 to 51295.
Edit 7/17/2022:
This one was also found on twitter, hard to read but seems that the ID was 51352. Now the range of 151 Mews could had been between 51259 and 51352.
Given this evidence, I'd like to believe that the distribution started at 51210 or 51250, and they were incremented by 1 each one, but this is just pure speculation.