Apologies for not getting back to this sooner - I actually forgot to check!
Thanks to everyone who replied and yes, the 'fetch' option works fine. I did see that actually but in the object drop down it said no objects in cache and for whatever reason it just didn't cross my mind to type something in that field like M42 and click fetch. Sometimes things really are as easy as they look!
Yes, it is totally brilliant and think I will devote Astrofest this year to mosaics. I suppose once I have some data of a wide field through the 152mm refractor I will then be posting about how to process a mosaic
Chris