Re: 15000 Thread Guide
As has been said I think that guide comes with the spool holder that fits on the back of the machine - I've never come across it advertised separately but Jim will know more on that - however there is no reason why you can't put the vertical spool pin in there and guide your thread around it.
I do that sometimes with metallic threads. You could also clip a bull dog clip to it, or even to the flip up lid (which I do sometimes) and guide your thread through the handles - they will even clip on the horizontal spool pin, if you try right to the right of it as you look at the machine.
Another option is to tape a paper clip exactly where you need a guide and put your thread through that.
Hope that helps
"Life may not be the party we hoped for, but while we're here we should dance". Anon