One of those things that immediately grabs your attention when you open the engine bay on a 356 are the air filters. The original Pre-A's used dual single Solex carburettors moving on to the two barrel P40 Solex carburettors for the later 1600's and both setups used Knecht air filters which are visually distinctive in both cases both having the raised pressed Knecht logo on the top of the filters.