Hard Decision, isn't it?
I'd have to agree somewhat with G-Benz on trading up to a car of the same mileage. I personally like the older Benzes myself, '88 and below, but that's personal preference based on how I think they are built now as compared to how they built them then. Personally I would invest in having the current engine rebuilt, either by yourself or a competent machine shop familar with Benz. If all else is running well with your current ride, why change? The tranny problem you are mentioning may simply be an adjustment that needs to be taken care of. In most cases, if the shift modulator is not set correctly it will make the tranny appear to flare or give the impression of tranny failure in the near future. I would fix this problem first, then have a leak down test done to find out where the oil is going on your current engine. I just think the money could be better spent reviving your current ride.
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan