Well, apparently, given the many interventions in this regard, the old question concerning the possibility or not to create Vassal modules for the old SPI games is still the subject of discussion.
When, in 2010, I discovered the existence of Vassal, I was very surprised not to find practically any module of the old SPI games to download from the Module section.
Subsequently, I became aware of the fact that the company that currently owns the copyright of most of them (Decision Games) had expressly requested to forbid uploading of modules of SPI games on the Vassal website : “VASSAL is not allowed to host this file or provide external links to the module in accordance to the wishes of the present Copyright Holder(s)”.
Now, one thing should be clear to everyone: what is currently prohibited is the sole fact of uploading Vassal modules of SPI games or provide external links to the module in the Vassal site.
None can prevent a guy in possession of an old SPI game from making a Vassal module “for his personal use” (here, in my humble opinion, human stupidity has reached its peak).
None, likewise, can prevent who have developed a Vassal module for an SPI game to report it on one of the boardgames related sites, such as Boardgamegeek and Comsimworld.
Moreover, as an AHIKS member, I have also noticed that in the last “K” (the AHIKS newsletter) in the “Open Match Requests” section there are numerous requests for old SPI games with a match code of “V” which means the use of a Vassal module for these matches. There were requests for Armageddon, Battle For Germany, Flight of the Goeben, The Green Field Beyond, Renaissance of Infantry and Seelowe.
This is the striking demonstration that SPI game modules exist and are available somewhere; the only real limitation is therefore that these modules cannot be uploaded to the Vassal website.
I believe, therefore, that anyone who wants to do this, can build a Vassal module for their favorite SPI games without bothering to violate any copyright.
Too bad that it is not possible to upload them to the Vassal site!