I don't know if your duett would be the same as a B18 544, but I expect it might be.

I found it to be VERY difficult to remove the transmission. The tunnel (designed for a smaller B16) did not allow clearance to pull the transmission with bell housing attached. Furthermore, that smaller tunnel made it very difficult to get the Allen head bolts out that hold the transmission to the bellhousing.

To do it again, I might just pull the engine with transmission attached. That would also allow you to really clean up the engine and engine bay. Also makes it easy to upgrade to the later neoprene rear seal if it hasn't been done already. (especially if the flywheel does need to be removed for a resurface)

Keep in mind, my experience was when I was 18, and my tool collection was fairly minimal.

The reason I had to do that job was a broken throw-out arm. I found it to be quite weak. I replaced it with one from a 122, which worked fine with the 544 linkage, and looked to me like a much better design.

All that said, I was working on a '62 544. And your late Duett is A) much newer, and B) of body-on-frame construction. So all that I experienced might not apply to you at all.
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-Matt I ♥ my ♂