Thanks for the advice on here in regard to the Wilkinson trems
I checked out their site on monday night and found the one I needed for my Squier Bullet. I got it in the post this morning and fitted it right away. I have to say for the paltry sum of 35 quid it works a treat. Its a steel block and I could'nt believe the weight difference between it and the original. It fitted the original six-hole setup just fine, I only had to cut a slight bit off the edge of the trem cavity with a knife which was catching slightly and a small sliver off the scratchplate. I dont know if I got lucky or not but as soon as I tensioned the strings, it balanced almost perfectly and only required a slight unscrewing of the claw to get the correct amount of movement.
I've been playing it on and off for most of the day and it has stayed in tune most of the time, just the usual amount of adjustment due to the new set of strings. It does'nt go off pitch like the original one did when I let it go after using it, which eventually made me hard-tail the bridge for a while in order to keep my sanity such as it is
There is definately a big difference to the sustain and tone on my instrument now compared to the cheap and nasty Squier block.
I'd strongly recommend this item to anybody wishing to upgrade the likes of a Squier although I'm not sure about the Fender trems, I do remember when I had a Japanese Fender in the eighties, having to replace the trem with a Kailer? unit of the time, which cost me over £100 all these years ago, it was a great unit but I really dont think it was that much better than this Wilkinson one I've now got.
So my other Bullet is getting the same unit too as soon as

Hugh.
P.S. The model I got was this one..........Axesrus 54mm Spaced Tremolo - Steel Block