Well i finally got the colour data and i spent some time processing the image properly and i am pleased with the results (although i think the colour balance still needs a bit of work.)
I applied a new bias frame and dark's (still no flats) and this seems to have removed most of the patten noise we were seeing the colour image has had the full gambit of pix in sight processing so i will include the new mono lum as well.
I also ran the weighting you suggested Rick (changed your equation a bit though haha) and now the total integration is 261 out of 291 LUM frames without a drop in the fine details. Very impressive. so now the new image data is as so.
Lum = 4hrs 21mins at 261 X 60sec
RBG = 1hour 50mins at 120sec X 18 per channel
total = 6hours 10mins
all at bin 1 at unity on the ASI1600MM cooled Drizzled times 2 in processing
Total stacking time and pre-processing time 12hours 52mins on an i5 4670@3.4GHZ with 16Gb DDR3 RAM. Raw file size for total integration 24GB. Final image XISF file 650MB.
I couldn't get a full image on Astrobin but this is a high resolution here
http://www.astrobin.com/265761/
I have also included a new copy of the LUM to show the improved background shot noise. I like the fact i can see at least 6 background galaxies in the close up LUM image
Regards, Grady