Not sure which 34 Mainship that you have. There are three different models of a 34. But look at my avatar to the left. The dinghy, about 9' is supported on the bottom with Weaver Davits. There is a block and tackle attached to the back of the hard top which pulls the dinghy up against the transom. The outboard is mounted on a bracket to the stbd side of the transom.
The Weaver Davits work great and also secure the dinghy to the swim platform when you are attaching the OB or loading it.
I think that this system will work with all 34 models.
Our previous boat was a 2006 Mainship 34T. We used flat nylon straps attached through the slots in the swim platform to pull up the dinghy by hand (not that bad with two people, one can do it in a pinch) and tie it off to the top above. This was just as secure as the Weaver Davits as the straps held it nicely at the swim platform and against the transom.
This method also should work with all three models. The following is a bigger pic of my avatar:
David