HP-41 modules and GPL

[pier4r]

Just throwing ideas around.

If a module is GPL, it shouldn't collide with the board, as the board can work without the module. Is that correct?

If a module is GPL, and one requests the source. One can gladly say "look I don't have them but I will try to forward the request". If the original author is not reachable to get the sources, that's it. Or not? I don't know if the middleman has the duty to provide sources he himself did not get. Does anyone with more experience know?

According to the recent -heated- discussions problems arise when something makes use of GPLed solutions and cannot work without them.

Those modules seems independent (I do not have a 41CL so I do not know) and a problem could be the absence of sources, that may have been not provided to begin with.

In other words. If I use a work from the past to not let it disappear. Should I honor the license forever, although the situation doesn't allow me to comply? In this case I mean: unreachable authors to ask them for the source.

I am not sure whether the GPL prohibits commercial returns, I think not though.