I was browsing YouTube and came across some old videos of the Tokyo Toy Show and other events from way back.
Seriously old and surprisingly good quality. Skimming a few of them, i've found several that show the Transformers displays and thought i'd share.

1983 - https://youtu.be/zqiQdw1zmuM?t=1m29s This would have been the year Hasbro discovered Diaclone and Microchange!
1984 - https://youtu.be/zjoQZeoI9pY?t=3m46s No toys but looks like a Microchange Twincast poster! And maybe some Devastator artwork near the end in some colours i don't recognise.
1985 - https://youtu.be/S5HbEFoFlO8?t=4m54s G1 TFs in the top 5 best toys?! This one has a lot going on, they're talking to some staff, seems to be about the origin of Transformers etc. Maybe Goktimus can translate it properly for us.
1987 - https://youtu.be/u6O1c0--Olo?t=3m4s Brief glimpse of Headmasters
1989 - https://youtu.be/WNLeZznp8kA?t=9m5s Star Saber etc. If i'm not mistaken, that's Takashi Kunihiro demonstrating the toys.
1991 - https://youtu.be/ROPU5ZSIq9k?t=7m13s Star Convoy etc
1995 - https://youtu.be/HWlXrzvUS2A?t=9m35s Generation 2
2000 - https://youtu.be/OI7As_WU5fk?t=1m46s Big Car Robots display

Bonus:
1984 - https://youtu.be/zjoQZeoI9pY?t=32s Gobots I think?
1984 - https://youtu.be/tQWSLsJSM9o?t=2m58s More Gobots. Packaging of "Robo Machine" instead of "Machine Robo"!
1986 - https://youtu.be/T6kUh_Ott3U?t=3m20s Voltron
1989 - https://youtu.be/WNLeZznp8kA?t=9m34s Typhoon Hurricane. Who didn't want one of these. Never did get one lol.

There's a stack of Sentai stuff and heaps of other things you'd recognise in the videos, so give them a look!