The clear acrilic could be casted using some mold type if their was a
tilt head on a contraptor 4th axis or use a UV curing light source to
cure UV resin into the freshnel lense.
thanks for your time,
My webpages on electronics
... comming soon
I've seen SLA discussed a few times on Reprap forums, couple of google hits:
very old thread: http://dev.forums.reprap.org/read.php?1,189,706