I have a number of different grub screws as well Michael but not worth the run across unless you happen to be out near me, you know where I am.
If you need something temporary you could shove in a standard size stud though would need to be longer than the original grub screws I have some studs and will look at the grubscrews tomorrow, could always stick in the post if I have any and the above size will let Lurker know what to look for as well.
The original part btw is listed as code 11076 key 3 .........M5 x 8mm