That's some extreme imaging Mike, I like it! Well done and thanks for sharing.
I notice you've also got the distant double spiral twins visible under M104, directly behind the "21" in your labelled image. I'm not sure how distant they are, haven't been able to find any literature about them but I always check for them in M104 images. Here they are in a HST shot:
http://antwrp.gsfc.nasa.gov/apod/fap...ro_hst_big.jpg (close to the bottom, 1/3 of the way from the left).