A fellow named Graham has gotten interested in stamps and is making a series of short YouTube videos called "Exploring Stamps." In each episode he takes a stamp out of a big accumulation and uses that as a starting point. The episodes are professionally produced and well-illustrated.
Sooner or later, he was bound to come up with a Machin, and this happened in Season (or Series) 2 Episode 17. In it, he talks about the Machins and also visits the new London Postal Museum, including taking a ride on Mail Rail.
Readers of this blog won't learn anything new, but I think it is interesting to see what he is doing on a popular social media site. On the page with this video, YouTube will helpfully list other episodes, some of which may indeed teach you things you didn't know. You can also go to the show's main page.
If you are a regular YouTube user, you can subscribe to this channel and then easily go back to it by going to your subscriptions page. You can also choose to be notified when new videos are posted.
There are currently 2100 subscriptions, according to the information shown. While that's not a lot for YouTube, I think it is for videos about stamps.
There are no ads shown before the videos play and no other indication of him making money from the videos. They are apparently a labor of love, and it's clear that a lot of labor goes into each episode.
Now click the link and go "Exploring Stamps."