OK just read this thread and happen to have my seat off so I decided to check.
Numbers on the bottom of the seat are (from back to front)
2300603 (Below embossed Triumph Logo)
4020217 (Below embossed SDM Selvazzano (PF) Italy
Sticker forward of that that reads "SDM 2300603 25~04~5"
Sticker next to that with care instructions in 6 languages.
Stock Seat? Gel Seat? After Market?
"Hamilton" - 2005 Thruxton