The PSA is a three part system. The first part is the metal and glass that stays with the machine. The second part is the upper metal frame with the film stretched over it and the third part is a loose piece of release film that floats between them. Are you talking about the release film or trying to rebuild an old frame?
The above is a respond from Envisiontec tech support. Do you mind if I ask who are you buying your parts from for your Envisiontec machine?