Standards and Supers all use the same aprons, any of the flat 68 onwards ones will fit but if you want the correct original one you need the 75 and later buldged fuel injection style but with 2 pea shooter cut outs which is a hard one to get.
Unfortunately both the expensive German Klokkerholm ones and the cheaper repro ones have the square cut out for the Alarm switch that was fitted on late Mexi Beetles.
No idea why as Mexi bugs used the single tail pipe cut out valances.
http://www.justkampers.com.au/111-813-301-p-rear-apron-valance-for-vw-beetle-1303-models-only-1970-1979.html
https://au.vwheritage.com/shop/111813301K/rear-apron-8-68-bulge-type/#esp_pg=2