Hello Freddy,
I've had a X5 in the 80's but no original lesley.
I dumped this organ because it had to be repaired and I didn't want to spend any money anymore.
For gigging I wouldn't recommend this organ at all because it's very heavy, the stand comes apart which is not easy to transport and the footpedalboard is very hard to handle.
The X5 for itself gives BAD sounds if you compare it with modern organs.
Abouth a month ago I played the VK8 (not the VK7, huge difference) made by Roland and I was very very impressed.
In my opinion just look at the Lesley and if you like this one (i've haven't heard it last 10 years but I think it was a good model, abouth 1 meters high)if it's in good condition I'd give it a chance.
I also agree with Uncle Dave that the Lesley makes the Hammond sound.
So buy a nice keyboard and hook it up to the L760 and you're ready to go