Crikey Clive you're only three years younger than me!! I still think we should keep up the sprog / grandadad thing though.. seems to be keeping everybody entertained..
Anyway Springs and stuff..
Lynn.. Judjing by your pictures you appear to have 'uprated' springs of some sort.. A higher rate spring means that it takes more pressure to compress it a given amount.. ie 100lbs to compress it one inch.. 200lbs to compress it two inches etc.. the spring may also be shorter (lowered). only real way to tell is to whip it off and compare it with a standard spring.
You also appear to have standard..old..and possibly knackered dampers fitted.. again the only real way to test a damper is to take it off and push it up and down checking for tight spots or resistance.. this though is not always successful as you have no idea what a new damper should feel like.
I feel that a combination of high rate springs and standard dampers may be less than ideal..in that the standard and possibly old worn damper will have difficulty in controlling the spring in rebound.
Ok how did it get like this ?.. the springs may have been fitted by a previous owner in order to 'improve' the appearance of the car (lowering) with little regard to handling performance.. hence they didn't bother to change the dampers at the same time.
Ok what are your options??
Keep the springs.. and as Fred says fit adjustable dampers.. this will obviously produce a harder ride than a standard set up.. but could work well on smooth tarmac..
Get hold of some standard springs and fit them with your existing dampers. cheapest option.. but you may then find that your old dampers are no good..
Get hold of some standard springs and fit them with new standard dampers.. (which is what I would do).. as Clive says, this is the best set up for normal road use. and would cost the least.. for what I feel would be the best result.
If you want to impress your friends you can always paint the standard dampers canary yellow.. download some Koni logos from the internet.. print them off and stick them on..Bingo!! (Joke)
I'd experiment with changing wheels last.. as this will cost the most.
The bottom line is.. it is up to you.. depending on what 'quality' of ride/ handling you are after.. and how much you want to spend.
You say that it has been polybushed which is good.. in terms of ride quality they are hardly any harder than original rubber and more compliant than original rose joints..
What do you think Clive??...sorry Sprog