This one has some similarity to the current discussion:Does a guy have any rights to reverse engineer a part that he will not get any other way and that he requires to rebuild his existing unit?

I have a severe dislike for the game of Dog-in-the-manger.

One could look at several branches to this one, but they all are contained in the 'not get it any other way' idea. If something is unavailable, I see no reason not to go to any required lengths to create it. There must be some specific examples where this might not be a good idea, but none that resemble the current topic.

and another: Do I have the right to copy songs that the recording companies refuse to release due to unprofitability?

The protection was granted to prevent profiting by others than those in possession of the material. If those holding the recordings are not going to release for purchase, I don't see any reason not to acquire them by any means available. I would add that I'd likely purchase them if they ever were made available...

I'd rather focus on the topic at hand. Is there any reason not to to generate the construction instructions on a piece of technology in the public domain, and then to go ahead and create said item?

The current issue has been clouded because there was claim of ownership of the design. It was fairly easy to establish that no such ownership of the design exists, and that it is indeed in the public domain. MQ clearly( or at least claims to ) owns an example of the design and is free to do what ever is deemed acceptable with it. I also own an example of this design. I am not in any position to tell MQ that I own it and they may not reproduce it w/o my permission.

It would be a different story if I had broken into the MQ archive in Phila and found the original drawings and fired up the office copier and made off with xerox's of the designs I wanted. That would have been a direct theft. I did no such illegal thing. That the end result of both actions is the same; I know how to copy the Peerless S265Q, and have done it repeatedly. This would creat an interesting conundrum on first inspection. It is answered by the means by which the public domain design is discovered.

Anyway, that is part of my feelings on the subject.
cheers,
Douglas