Yeah, I don't suppose the PortaDrive comes up on eBay too often!
My PortaDat came from the first batch of 50 sold. I've always been an early adopter! It did sterling service but I can't help reflecting how much more bang for buck is now obtainable from the likes of the R-44. I chiefly keep mine because it seems more likely to play DATs from any other machine than the rest in my collection, all of which now seem rather fussy.
I hope HHB remain as helpful as they were to me back in 1984 when I used their facilities to edit my first commercial CD for Philips!