MOT Fail - Broken Rear Coil Spring

[rlievens]

So my car failed MOT today due to the left rear coil spring having snapped. Mileage on 66K. (2012 2.0 cdti sri vx-line) I can't say I have noticed that the coil spring was knackered having driven the car etc.

Anyway decided to replace both rear coil springs so I've managed to source 2 Astra J SRI springs (Part No : 13340838) off eBay for 100 quid but have noted in the Haynes workshop manual that I should probably use new shock absorber bolts. 

Anyone know what the part numbers are for these bolts or are they of the generic type.. ?

Replacing the rear coil strings looks easy enough or am I missing something here? (Yes I have bought a torque wrench : have axel stands, trolley jack ) 

Thanks

I would imagine you would notice a snapped spring, but apearantly not

If you are talking about the SHOCK absorber bolt and not a SPRING bolt (if that exists) then the partnumber can be found here: https://opel.7zap.com/en/car/p10/m/0/2-8/ (number 12 on the list)
GM 11610587

Here you have the partnumber for your springs (which you already have): https://opel.7zap.com/en/car/p10/m/0/3-1/

I also need those bolts because I have a leaking shock absorber I need to replace. The expensive flexride ones :(