im sorry but this wil be a long long one...
info i gathered about the anpanman pilots
WARNING: most of this info came from some yt coments i found so take it all with a HUGE grain of salt
lets start with some actual relyable sources:
the credits say that the pilots where dirercted by some tetsuo yasumi guy and animated by "studio Märchen" who worked on "nippon mukashi banashi" wich many pepole tough this was from but it wasnt as we soon wil see.
as for what Yanase himself said about it in an intervew in the late 2000s he had very little involvment and it was made inpedenently by forbel kan.
it was aparently shown on places such as libraries and street shows in 16 min tapes (whatever those are)
the frist one was released in 1984 and the second one in 1987 (wich is odd since is the year the TMS anime started production)
aparently there where plans to adapt "anpanman and gorilaman" in a third episode but it never came to be (probably bc TMS was already working on soreike anpanman) and its unknown how far it got into production
strangely the vas arent credited anywhere in the short and since the japanese audio is lost its a total mistery. i beleve theres a chançe anpanman could have been voiced by toshie kusunoki who voiced him in the musical Märchen anpanman/ringing bell records but that was like almost a decade before but i stil beleve in the posibilty.
if you read it all from an unofical anpanman historian to an anpanman purist thank you!
*Cracks knuckles.*
I have been studying Pilot Anpanman stuff for over 2 (almost 3?) years now and feel like I've been called to fulfill a prophecy, so thank you.
To start, a decent chunk of what you said is proven correct. Yes, the Pilot episodes were directed by Tetsuo Yasumi and animated by Studio Marchen, whilst being made by Forbel Kan. Yes, these tapes were played in places like the mall, library, you name it. Anywhere that had a small overhead TV with public access was fair game to these tapes.
The reason these had aired as they did was because they were being used as audience "test samples" i.e. seeing how the consumer would react to an initial product. It's a market strategy. At this time, animating the Anpanman comic and anything else was still merely a test idea. There were plans for the third tape you mentioned, but it didn't come to fruition in Japan because they were trying to aim for a new angle plus the perception and understanding was that Anpanman needed upgrades.
The initial episode 3 idea was scrapped, but another one was made in its place. Around the time Soreike! Anpanman came out, there were still tapes for libraries and malls and other places still being made for spaces that didn't have cable TV or could otherwise broadcast TV, which eventually stopped after public TVs gained better access to cable TV and could therefore show Soreike! Anpanman.
Unfortunately, however, most of those tapes are lost media and the Japanese versions even moreso.
(These are even harder to find considering that most were just made to advertise, not to broadcast).
Japan wasn't the only country that Pilot Anpanman had any relevance. Other official dubs existed in greek, urdu, arabic, and other languages. Some of the dubs for that exist on Youtube for the first episode, even. There were (at one point) bootlegged/fake episodes being made in other dubs that were very poorly representative of Pilot Anpanman content as well and look nor sound nothing like it. As far as I know, they're not sold around anymore.
Occasionally, a Japanese auction site will auction off a random episode tape here and there that is legitimate but expensive. I've had a go at getting them numerous times, but to no avail. It's hard to find the original pieces of media that started this odd appreciation people are starting to have again and even harder with other dubs and bootlegs.