I am not a copyright lawyer, but....Copyright laws protect the original artistic works for the life of the author +70 years (thanks to the AU-US Free trade agreements), but circuit layouts hold their own special protections which is based on copyright protections - in Australia, this is up to 10 years form the original creation of the layout plus 10 years from when the layout was first made for a maximum of 20 years - I am not sure of the equivalent rights in the US, although suspect they are similar. So a circuit layout may only have IP protection for up to 20 years, but the same layout *may* concurrently have copyright protection for the lifetime of the original author +70 years - this would be a point for a copyright lawyer to answer. Another point I just noticed is that IP Australia identify circuit layout protection to be for "integrated circuits". What the consequences are for non-integrated circuits would be, sorry, but I don't have any experience with this aspect of Australian IP law, so I just don't know.
If the circuits are quite old (older than 20 years), it is *possible* that the IP protection for the circuit layouts have expired (at least any circuit layout rights, but copyright may still exist) - but I would check this very carefully across all major jurisdictions (AU, US, Europe etc).
Re your own hand drawn schematics, whilst they would be your own artistic work, the substance of the work would not have been created by your own intellectual merit (see case histories of Nine v IceTV in Australia) so you *may* have issue publishing layouts of a circuit that you do not own the rights to. Copyright can be assigned so the person/company taking down previously published layouts is likely acting within their rights to do so (so the assertion that this is a jerk" "squelching" the designs is probably unfair) - this also suggests a desire not to have the circuit schematics out in the public domain for whatever reason......
As to reverse engineering, I can't comment, but at least in patent law, if the end result of the reverse engineered thing did the same as the original item that was protected by patents, then the reverse engineered thing would infringe those rights....i.e. reverse engineering is not a defence against patent infringement ... Against copyright infringement? ... I don't know, but are you prepared to be a test case???
So if you do draw your own schematics from the layouts and publish them on the internet, whilst they may be your own work, because of this person's apparent desire to remove publicly available schematics, I would not expect there to be no backlash from the copyright owner as they have clearly decided they do not want the circuit layouts in the public domain.
Sorry, I can't be much more help than this.
Phil