Lanier Dart?
First, MEK is a solvent and very dangerous to the eyes.
As far as the soft mount is concerned, the plane comes with wooden engine bearers that are part of a wooden frontend assembly. I think you'll find that the firewall is quite thin and made up of cheap ply - not aircraft ply. Even cutting the engine bearers might be a big chore to install a firewall soft mount.
RCPAUL