Hi Peter!
If you need some hints for making the 10D following your wishes
in astrophotography let me know.
Understand why you want to use the filter. Be careful when glueing
the filter to the chip. Fluid glue moves fast from outside to inside
between chip and filter.
We experienced this trouble. But we have a friend who is musician,
technicians would even not think about that,
who cooked the
chip in 60° Celsius water and got rid of the glue on the chip! 
And the camera still works perfect.
Ready for 10D help if needed.
Gerald