380SL 1981 questions

[AlexK]

Hello there, my first post.
Maybe I am asking answers on too many things at rigth now.

I am trying to get a 380SL 1981 on the road before summer.
Things to do are a kind of major:
-need a chain conversion
-need to replace the transmission
I have a mechanic to do the work, and trust him.
We kind of verbally agreed (for now) on the following:

-1 one day labour to remove the engine including the transmission
-2 one day labour to do the chain conversion
-3 one day labour to re-install the engine including the transmission
provided that nothing major things happen (breaking bolts etc.)
therefor 3 days labour, not including setting up idle control etc.

I supply him with the Chain Conversion Kit and a Rebuilt Transmission.
The mechanic says there is no need to remove the total engine for this.
I think that doing the chain and reinstalling the transmission, would be easier on him with the engine removed, and it also says so in CHILTON # 48300. To trade-in the transmission I need the Torque Converter and the Bellhousing.

Have you got any opinion on that?

Thank you so much.