Real weird problem here.
If I search car part sites by REG for brake discs it tells me I need 256mm discs. Also eBay tells me this. Now the dealer tells me I need 260mm discs which some eBay sellers are also selling yet eBay tells me these discs don't fit my car.
So I measured a disc using a metal ruler, I leveled the ruler on an end and rotated it at the other side until I found the longest distance and I get it as 258mm every time byt I understand this method could be out by a mm or so but it should be pretty accurate.
Now there's no 258mm discs for my car that I can see.
So do brake discs get thinner from corrosion, could these discs really be 260mm but have corroded around the edges by 2mm?