The higher rebuild cost for this xmission seems to be because it is a 5 speed. The 4 speed in an SL500 is considerably less costly to rebuild. I didn't know how to use the 1st gear start in my SL300 for the first year I owned it and rarely use it anyhow.
I would think that the shop where your transmission work is being done could tell you what stage the rebuild process is in. No? Are they waiting for parts?

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