Thanks for the extra pics. This has confused me even more. In two of the pic's you will see your Long Shaft (20") Outboard is clearly mounted to an added piece of "homemade" grey timber in the centre of the Short Shaft Transom (15").
In another pic you will see that the mounting bracket (normally for an auxiliary motor) has been removed from the Port side and then re-bolted in the Centre of the Transom... then, the Outboard has been re-mounted on what was the auxiliary motor bracket!
I also note there has been yet another different "homemade" auxiliary motor bracket added to the Port side.
This is the best bit, I respectfully take my hat off too the person who has managed to adapt an 1960's OMC Control Box to the throttle and gear shift of a Suzuki Outboard which never had an option for remote throttle and gear control, let alone cable steering!! Note the cut in the Starboard side of the cowl, to allow the throttle cable pass through
Your boat will be a wonderful "lake" boat. I'm sure you will get plenty of enjoyment from her. One piece of advice I should offer.. before you tow her too far, remove the trailer wheels and hubs then repack or replace the inner and outer wheel bearings.