I have a logo I'm trying to reproduce in inkscape. The logo is based on two concentric circles, with segments removed and curves extending inward and outward around the circles. One extension extends both ways, so some sort of T-intersection with the curve will be necessary, or a second extension that runs into the first, collinear at the join.

I've done a little experimenting, and I think I can eventually cut a circle-like path to remove a quarter segment, but then it isn't a circle anymore, with any node movements distorting the curvature. If possible, I want to lock the circular segments to their original curvature and center point. The segments to be removed are less than a quarter, so the endpoints need to move to less of an arc along the circle path.

Here's an example of what I need to do (the logo doesn't look like this, but the cut-curve characteristics are similar)

L R L xxxxxxx R L xxxx xxC R L xxx xx R L xx xx R L x xx R L x xxxx R L x <-xxxx R L x xx1xxx2xx R L x xxx C xx R L x x x x R L x <--xx x x R L x x x R L x x | R L xx xx V R L xxx xxx R L xxxx xxxx R L xxxxxxx R L R

The curve x's represent the actual line drawing. The C's represent the points at which I would like to cut the circle and have the freedom to add bezier extensions. Extension '1' can have a smooth curving joint with the cut point. Extension '2' only need meet extension '1' collinearly, and more or less at a right angle to C. The L's and R's are only intended keep the mail client from mangling (hopefully). They line up on the left and right columns, respectively.

On the second of the two circles, the two inward extending curves will have to be joined in a smooth intersection after some bezier curvature.

Overlaying background-color circles to represent cutout arcs would be less than optimal, since I may want to do curved endcaps and drop shadows or other filtering (when supported) on the unified curve.

Can anyone suggest to the newbie a good way to make a stable, easily manipulated construction of the above curve in inkscape-cvs?

Thanks.