No reply, i guess is a serious question, ok, without keel your gib sea can make a 180 roll with you inside and turn turtle , the cost to drop the keel and put the keel later on is expensive, crane or travelift plus labour and the keel shipping
, just figurate,
the bolt holes can be pluged with epoxy
or wooden plugs Lol, anyway if you still consider the rivers try to figurate a way to put ballast in the boat or!!.......