Crusoe,
at the risk of going slightly off topic, as a mechanical engineer and enthusiast, I am curious as to what process you used to limit interaction between the RTV and the mold elastomer, was it a coating? or was there something else you did during the rubber vulcanization process (ie. in the vacuum chamber). On a personal note, I would expect you would want something a bit more resilient to detail than an low temp rubber, have you tried using strait up two phase epoxy (green stuff) with a lubricant, might be better and less expensive.

Congrats on your minis.

Adam.