Your cold start issues are almost certainly plugged up idle jets. Been there. Done that. lol My bike used to be a real pig to try and start and would bog coming off the line and required lots of feathering the throttle to get it to take off smoothly. I went through the carbs and found that 2 idle jets were completely plugged and 1 was partially plugged... Well there's your problem. lol
Your bike looks like it's, overall, in very nice shape.
IW