Hi Roger,
Here is one of my cropped images of PGC23496. You need to build up your own reference library of images asap. You have made a great start already. Then as you get better seeing replace the older images with better ones taken with the same equipment and exposures. This will help with the blinking. Use DSS images from
http://archive.stsci.edu/cgi-bin/dss_form (the Sky 6 images are pretty much useless). I use the DSS Red and IR survey to check any suspects against as well. Astrometrica is fine for your ball park magnitude estimate at this stage and any discoveries are fine to report with this so long as you note your sources.
Alex Wassilieff from New Zealand did some great work on a CCD atlas and this is very useful. Also try looking at the DSS images as negatives, often stars near the nucleus may stand out more. We really need to talk on the phone, there is much to be gained by all , if you would like to please pm me with your number and I will call you tonight.
PeterM.