Winkio doesn't go on this forums anymore. He basically left. He probably does fly back from time to time, but for the most part, buh-bye mi amigo. You can probably contact him via e-mail.
Falcon is a member of RMRK. You can contact him through the the forums there.
shdwlink1993 has been not so active lately, but has appeared a little back. Don't know if he'll appear again, he's quite a quagmire now...Which is sad. :/
It's definitely acceptable, as long as you give credit. For a research paper, you don't ask your sources permission to get that particular information for your thing. You simply credit them or acknowledge...
However, in some cases, you may do require permission from the script authors IF the project is commericial (You plan to sell it). If so, then try and contact them with high priority. If they don't respond, it's probably safe to still do it, but who knows...