Hi Robbie, I recieved a PM from You yesterday and I also reply'ed yesterday!
The weight of my bass is appr. 4,8 kg. that is a very normal weight for a SR5 due of the standard used woods. (sorry but I have got nothing else but my bathroom scales to weigh the bass)
Since you are looking for a SR5 under 4 kgs I'm affraid I can't help you. I personaly never saw a SR5 under 4 kgs. i wish you luck with the search! As I said, it will not be easy!
Regards,
Dirk