Still have my SWF blade holders so that could be a cure but from memory they were very worn,they go all floppy and the blade tends to roll over too much with side to side movement.
The whole thing is a PITA considering you read "this part fits your 914"

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Bought a new set of wiper arms from a well known west coast US supplier and received them and they didn't look right,turned out they were 930/SC US spec LH drive arms,same BS about fitting my car which they didn't.
Strange how I got these as I was in the 914 section

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Every cloud has a silver lining as they say a guy on our countries biggest auction bid up on them like crazy and I returned 2.5 times my cost but really not how I like to buy as sending parts half way back around the world can't work for me.
Rant over.