I never experienced a loose stock handlebar/master cyl, but I would sand down the 1/2 clamp a bit (the one which holds the bolt heads) until I got a good 'purchase' on the handlebar. It shouldn't take much sanding.
Install clutch master cylinder, use the vacuum pump to bleed the system. just under 1.5min lever grabs right at the top. Change oil and filter, Check bolts all around the bike for tightness. Check front and rear brakes, Coolant level, Syc carbs, Brake fluid levels, Check tire pressures, Check fork oil level, Check all carb boots,
Also question clutch master cylinder that was order did not have this little lip that fits under the lights housing.. Also it was kinda loss on the handlebar. I had to rap the handlebar with leather strip so the clutch master cylinder fit tight.