I have attached two figures:
One showing the position of Jupiter relative to the focal plane for a raw
image from the beginning and end sequences (addresses the "filter scratch"
question); the other includes the most recent blue image that I have prior
to Mar. 19.  Fortunately it has almost the same central meridian (Longitude
I).  Most of the equipment was the same, but the barlow was different and
resulted in a bit larger image.  I think that the seeing was also better on
the Feb. date (Feb. 17 04:16 GMT)
-Don