I'm sorry for not offering any possibilities myself and now start nitpicking, but National Party might be a bit problematic this early on in regards to the NS-dictatorship and a question on whether Austria is indeed a nation on its own.
Anyway, thank you for your ideas, here are three possible suggestions, if I could again ask you, which would you prefer?
ÖNVP - Österreichische Nationale Volkspartei - Austrian National People's Party
DPÖ - Demokratische Partei Österreichs - Democratic Party of Austria
LKP - Liberalkonservative Partei - Liberal-Conservative Party
how about Austrian Reform People's Party?