I have a fair amount of experience designing raised deck boats and I can tell you it's much more difficult to get a broken sheer (raised deck) boat to look good then a conventional sheer. There are a number of "conventions" we can rely on for "shaping" the sheer, but the biggest one to remember is the boat has two sheers, the lower and the higher, broken element. The lower one has to be suited for a broken sheer or it'll look silly.
A continuous sheer (common traditional type) usually has much more sweep (belly) to it and this belly is located further aft then on a broken deck boat.
Here are two of my broken sheer designs, both substantially larger then a Vacationer. Wetlander's sheer is just about right, with the belly's deep point being nearly midship, which is not the case for a continuous sheer. Commonly a regular sheer has it's lowest point at 70 to 80% aft of the stem.
Lass's sheer is a bit of a compromise, having her lowest point further aft then desirable, but I needed headroom below decks.
The common element is the lower sheer shape and location. To make a broken sheer look right (lots of trial and error included) you need to have the lower sheer's belly further forward then seems natural if it was a conventional sheer boat.
On Weekender/Vacationer, with their double rubs, you make clutter up the sheer with an addition one further above, hence I'd remove one of them (the lower).
Now, both of these examples are flush decked boats, but the sheer could have stopped and dropped down to it's standard (lower) location. The same rule applies, if the raised portion is in the forward half of the boat.
Also note that the upper sheer on my designs tapers down toward the lower sheer as it gets closer to the bow. This is a common element on all raised deck or broken sheer boats. If this isn't done, it's looks wrong some how.
If I was doing what you're contemplating, I'd redraw the profile of the boat and move the belly around to suit the new raised potion, rather then rely on the original sheer. This is because a single sheer boat (conventional) has more "spring" to it. A broken sheer is generally flatter, which is another reason why it's difficult to convert a standard sheer to a raised one and have it look right.
Sam Crocker (as has been pointed out) was about the best at developing broken sheer lines that were pleasing to the eye. My personal preferences differ in how he handled the transition area, with Crocker using a gradual sweep up and my preference for a tighter curve, but this is a minor styling consideration.