I don't see much evidence of protective coating either. Oxides on aluminium do protect, but ferrous oxide is porous. The thing is though, it will probably sell for that price to someone thinking it just needs cleaning and assembly. Not sure why folk think that newspaper or old curtains protect anything, especially in a damp garage.
Frame number looks to be around early part of 76, so will be tax exempt from next April - something in its favour I suppose.
Ian
