Just found this, currently in Wolverhampton but will head to west Wales when I sell the house, been in the attic 10 years or so . Looks OEM has part number 483.1.019.1A and '26 gen 2000 marked underneath , some slight marks in paintwork, mesh for vents missing. £500
Your loft find seat unit is most likely for/from a mid to late 2001, 2nd generation 748R, the one that had the engine update (different Pankl con rods) and full Öhlins suspension. Yellow and white is the correct colour for the UK spec 2001 MY. The superbike 748R graphic is different to the 1st generation 748R but will fit the earlier model. Pretty sure the seat unit will also fit the final generation, slab side fairing 748R but that only came in red as standard. Not sure what the market place is like today but £500 is, IMO, a good starting point but you might have to be a bit flexible Andy
Yep,, probably a bit high but prices on eBay were /are all over, only one similar was £400, but now gone, copies a few £100s, but one listed at £900, mad
