Just an update on this post, managed to get an actuator off a fellow member on here, many thanks to Jon Wildsmith, you saved my sanity.....
It was a second hand unit that works a treat so anyone out there who finds themselves in the same predicament as i was in trying to find one they are out there so just keep looking.
Just a tip on fitting one if people dont already know this is, went a treat for me, 1st make sure the acuator rod is extended as in the locked position, do this by just connecting the power, with ignition on, in low box, switch to 1st position RR, then ign off, your acuator rod will now be extended, dissconect from plug, jack the rear offside wheel off the ground, put lowbox into neutral so you now can spin wheel freely, lever the fork in the diff into lock position so now wheel is locked, actuator will now slide into position and easy to thread 10mm bolt to fork, dont worry about the small gap between casing as this is the trick...reconnect plug, turn ign on, switch diff lock off and hey presto the gap has gone and acuator is flush, tighten 4 bolts up, replace sensor cover, job done.
Hope this helps you ppls out there...