Sail drive issues (damper plate)

[Shane.firkin]

I have a nanni diesel 3.110 29hp with sail drive. I took a knock to the prop while motoring (something submerged). In any case when this occurred I lost all drive and there was a grinding noise coming from the gearbox area. The prop was checked and okay and the oil in the gearbox is clear. I have no forward or reverse drive. Discussions with friends suggest the problem is the damper plate. Intent is to have the engine disconnected at the bell housing and moved forward to allow repairs. I want to know more before we get stated. Does anyone have any diagrams or illustrated parts breakdown of this unit?
Cheers
Shane