You have got a great looking SL. I like that front bumper and love the Xenon lights (I am considering the lights as well). I like the model 97 front fender panels and model 99 taillights and side mirrors!
I have been thinking whether to upgrade my silver-gray 1990 300SL or whether to buy a newer SL first, but after seeing these pics, I think I will stay with the current one!
I don't know how far you are by now and what problems are solved, but about the flashing top-switch: I had a flashing switch as well because my hydraulic system was not able to close the hard or soft top anymore. It took a new hydraulic valve to get it working again.
The indicators/hazard lights sound like a hazard switch or combi-relays problem...
with a minor 600+k