Yes, can we throw in some more maps (specifically re-made 1.6 mill aka de_cpl_mills)? There are even de_gold_dust and de_gold_dust2 if you want the Goldsrc (1.6 engine) versions of those maps, too, but I haven't played on them in CSS. I did just download them.

I was also trying to find a 1.6 train that works on Source (direct-porting Valve property maps is not allowed), and I think this is it: https://gamebanana.com/maps/158334
de_train_modern