Thank you! Plone 4.3.19 can be installed and runs on Tauthon and products can be installed with these versions pined:
RestrictedPython = 5.1.dev0
zope.security = 4.0.0
zope.proxy = 4.1.0
zope.pagetemplate = 4.0.3
RestrictedPython warns though that it is only supported on CPython and that use on other Python implementations may create security issues.