Thanks guys, really appreciate the support here.
A couple of the grub screws have seized in the barrels and chewed up. I was careful, but I can only suspect this damage was already there - the action was stupidly high when I picked it up, but I put it down to not being set up right. I may have discovered why now! Never mind, you pays your money, etc.
I had a look for replacement indentical saddles online, but I couldn't find any with grub screws. I was unsure whether other bridge saddles would fit the existing bridge plate, hence sticking with same as. Given what you guys have said though, I shall see what I can pick up! I don't mod my basses much, hence being a bit unsure about it all.
Once again, really appreciate the help.