Yeah, they do go splat after so many years, I think was one of the first things I've replaced on mine as not only they didn't hold the bonnet in place but it was a struggle to lift it up too. Luckily they are cheap and easy to replace. Hopefully they'll get your screen fitted right!
1997, 4.0 LWB X300 - Unlucky car but still a daily driver. 1988, 3.6S XJS - Never ending restoration project. 1994, 3.2S X300 - Accident damaged, October 2015. Gone! 1994, 3.2S XJ40 - Long gone.