Hi Paul, you can find new ones on the web but my experience is not to go for the Progressive types from a German company, I thought they would be ideal for my race bike. I cut the spacers down to try and reduce the pre-load on the new springs
When I got my Monty to a suspension specialist at the end of last season he could not believe I had ridden the bike let alone raced it - way too long, much too hard, wrong in every way
If your forks are apart, it may be worth putting them on a good flat surface and check your stanchions, mine were both slightly bent, not unusual in older bikes I am told, I suppose forty years of braking and abuse will take it's toll
In the end I had new stanchions, custom springs, new synthetic bushes to reduce "stiction" and other internal mods. Cost a lot of brass but now they do what they should and work very well with a good window of adjustment
Hope this helps a little, as usual ask one question and get a million answers, sorry to tell you more than you wanted but I wasted a lot of time and money trying to get mine right and had listened to a lot of BS here and elsewhere. When I went to specialist he transformed my bikes handling and steering