It would be helpful to know what you are referring to.
There are fan made SFC:OP based specs available now for both Andros and SFB style Tholians. They are not 100% accurate but they are FUN to play with.
As for Andromedan models, Anduril has made a fleet of TOS/SFB ones, P81 made two TMP ones and Darkdrone kitbashed a series of TMP ones from them.
Brezgonne's gold standard SFB Tholian models can be found here:
http://dynamic5.gamespy.com/~sfc/files/pafiledb.php?action=category&id=1&start=20&sortby=creatorHowever, I myself prefer TMP Era Klingon Academy style Tholians with a few kitbashes by Terradyne and Hollis J. Wood's TNG Tholians (retextured by me) thrown in.
Qapla!
KF