coping sled for spindle

[johnnyb]

I'm making some windows and looking through my spindle cutters I do have the correct mould it's a 6mm quarter round with quirks. I also happen to have the scribe cutter. what I don't have is any sort of coping sledge to run the scribe. the tenon will be started on the multico then the scribe done on the spindle. then the mould then the rebate( on the rails anyway)
does anyone have any nice designs for something to achieve this. obviously a square chunk of wood and a false fence would work fine.

 

[johnnyb]

square edged chunk and a false fence it is then! the beauty of this arrangement is it can't get pulled in( cos of the tenon end on the false fence(