SK48:
Super V, as you can see we all have slightly different shift assemblies. Rex has a shifter with detent notches and a lock button. Thats what I have in mine and it works well. My shift pattern has been reversed so starting from the back it is P,R,1,2,3 going forward so you are up shifting as you push forward. Lots of V-drive cruisers don't have three speed transmissions and they work well without them. I really never use first or second for recreational boating, just put it in third and take off is just fine. Why don't you just try starting off in each gear ( if it has first it probably will just rev up and go no where) If you start off in the other two gears I would think you should feel the difference between second and third.
What prop is under the boat ? Steel or brass ? Just curious. Brass in good shape with a 15 marked on it?