Don't know who changed the part..I am simply telling you they did not have the new modified relay changeover until after your manufacture year,....so ...Somebody change it and that also does not mean the new one is now not failing..the points wear out and the sockets get corroded..like any electrical part.
What I do say is IF you have the old relay, I ask that it be changed REGARDLESS of it's condition b/c they were an inferior part..which is why they changed it in the first place. And it was probably them b/c BENZ knows all about the original OVP problems..Everyone does ....
It was probably the FIRST thing they did before putting it out for sale. I am sure they did not want a nice StarMark Benz on their lot that would not start !!! And if your car still had the old OVP and was a Star Car, I would be right in their face about it...
Most Techs have the new# relay in their tool box so they can just pop one in there on a complaint like yours.. simply b/c that is much easier than trying to find an OVP glitch w/o a scope and testing equipment.
They are that NOTORIOUS !!!!
So, next time you have the problem, I suggest you tap the relay and retry ..
If YES, I would chance the price of a new OVP..that's all.
I would also pull it and look for burn eveidence at the pins and I would pull the fuse on top and clean the spades..that may be all that is needed.
Or have it diagnosed by someone with the equipment to do so.