This could help those of you having difficult cold start.
For the longest time I had problems with my cold start, I had checked every thing along the line & all seem to work properly, today I decided to go after one thing that is often overlooked, the ignition switch, (brown piece) in order for the starter relays to do their job they need to get right amount of current, otherwise they do not work right prompting a difficult cold start.
The points at the ignition switch have a certain life span no matter how many times it gets cleaned as there are other parts that simply wear and eventually need to be replaced, by replacing you are sure that all current going from your ignition switch is the right amount to the electric components.
This part is available at:
http://www.autohausaz.com/search/product.aspx?sid=cdddcj2e1dljgvrhpn1s5avw&makeid=800016@Mercedes&modelid=1193341@280SE&year=1970&cid=25@Ignition%20Parts&gid=4520@Ignition%20Switch