I also mounted a glass 1950's dialco domed 1" light to the top of the engine cowl as a stern light. It has a quick disconnect so the cowl can be removed easily. I've never seen it done before, but, it works well being higher than anything on the boat.
This works great. I'm not a fan of poles, body holes or anything that can possibly get hung up on lines.
It's a newer merc 40hp, with vinyl graphics. It's a bit heavy, 200 lbs about.
I often find myself needing to get out of the way of pushers and flying carp on the Illinois River. The power is great, however, I wouldn't want to go with anything more.
I have been working on an aft deck like this for my Vag but the only problem is that my rear seat is much closer to the transom than yours. By the time I cut enough out for the steering and throttle/shifter cables there won't be much deck left.