Anne, while you have the springs out would be a perfect time to check the condition of the wishbone bushes, because it's very difficult to check them when the wishbones are under load from the spring.
And of course while you're at it you should also check the upper and lower stub axle joints
See
Resources - Bristol Cars - Owners and Enthusiasts Forum
When the time comes, there is quite a bit of information on this site about dismantling the front suspension. It may also be worth contacting Bristol in advance to check that all the parts are available and the cost.