I've not found a lot of old things in quite awhile, but here's one that's off the beaten path. For this you have to stray away from the TT-F community and over to our brothers and sisters on Tycoonez.Com:munity.
There on the forums you will find Kadlovy Paintings
, which forum member Kadel started drawing in 2008. Initially these were a few houses, and then a few stations. It looks as though these may have been donated to the CS Town Set and Station Set projects.
More uniquely, though, were a pair of buildings that were eventually released as a NewGRF. The first is the Libeňsky Lighthouse building in Prague.
As you can see from this screenshot, it blends in well with some of the modern era buildings from Total Town Replacement Set.
Even more unique, however, is Kadel's drawing of the proposed Czech National Library from 2007. This is very unique because the winning architect designed it to look like a giant mound of slime mold. This unique design drew a lot of praise and criticism from architects, politicians and many others. Kadel managed to capture the spirit of it and include it.
You can find the released NewGRF
on page five of the discussion topic, along with a list of parameters for the Lighthouse building. It was later reported that the Library was not being displayed, and unfortunately it appears that Kadel stopped contributing to the community in 2009. Kadel also donated this work to the CS Town Set, but it appears that this set was never finished due to a myriad of issues, and its work is currently idle. Still, you have this one NewGRF that you can now add to your list. Out of respect to the Tycoonez community, please don't jump over there and start new discussions on this, as the author is no longer around to support it. The author, however, did leave behind their NFO and sprites, but no license. One may presume to at least use this for your own personal use.