164E calipers used with vented discs are ATE, they are different from 240 calipers.
Remanufactured ATE calipers are available from the USA as well as the usual suspects.
Skandix and the other usual suspects still stock new caliper pistons and seal kits.
As for replacement 164E vented discs, they are available here -
https://www.ebay.com/itm/401995104815