The Takara logo should be different. I think the 1986 Transformers' Takara logo is the "thin" font inside an oval (example). Otherwise it could be the "black boy" logo (example) - I have 2 1986 Takara TFs but they're at home. The reissue uses a different logo which looks like this.

The reissue also has no "clip and save" bio & tech specs on the back of the box (since they have tech specs cards inside, here's an example of a Japanese G1 box back w/ tech specs and robot points), instead there's lots of legal blurb. Reissues also have something like "年齢対象15才以上" ("For Ages 15 and Up") written on the back - even if you can't read Japanese you can still recognise the Hindu-Arabic numeral "15."