The spec weight on my 2003 232 is 4092 lb (dry), plus 600lb ea for the F200's. I figured that my wet weight was around 7000lb, plus trailer (2000?). I really should weigh it, as I'm surprised to hear that some are seeing 10000+lb fully loaded. One thing I've adopted recently is that I don't use or fill the Aux tank. For my use (Monterey Bay), I never have over a 30-mile day, so keeping the main tank up around 70 gallons is plenty of range for me. Up until now, I had kept both tanks full. Emptying the Aux tank and not filling the main up to 90gallons removed nearly 500lb from the cockpit, which really made a difference in performance of the boat. It didn't however, lift the transom up as much as I hoped - I'm still dragging the skegs of the motors in the water when fully tilted. Looking forward to a repower some day to the new 4-cylinder motors. Saving 200lb on the bracket should surely help my motor tilt problem.
I keep it in a slip, but for annual haulouts, I used my son-in-law's 3/4T Chevy Duramax. No problem at all.
I think there are a few different things that come into play here, of which the first would be the year of the 232 Gulfstream as up until 2005 the dry weight is listed the same as yours at 4,092 lbs. That being said, it looks like in 2006 they increased the dry weight up to what it's currently at, which is 4,605 lbs. I'm not exactly sure what all was done to the boats that added an additional 500+ lbs, but it appears to be something that they stuck with and are still doing today. I'm assuming that they must've done something with the stern of the boat because of the additional weight that 4 stroke motors tend to have over 2 strokes, but I'm not certain. Though I'm thinking that's probably why there are the discrepancies about the boats as one like yours that is slightly lighter, if it had a single outboard on it with next to no fuel in the boat, no tackle, gear, bait or other equipment. Then it'll obviously be considerably less weight, and the overall total will be quite a bit lighter, especially if it's on an aluminum trailer compared to galvanized, as they typically weigh less. Comparatively, a newer boat that has the 4,605 lb dry weight with twin motors, a full fuel tank, full auxiliary tank, loaded down with gear and on a galvanized trailer is going to be another story entirely. On the GW website they say a brand new 232 Gulfstream with twin F150's on it was tested at "7228 lb. (including persons, fuel, water, gear, engines & accessories)". Of which I imagine you could probably drop at least 300-400 lbs of that weight considering it includes persons, that being said I'm sure that the testers had as little fuel in the tank to get as good of fuel economy numbers as possible. I'm thinking they probably had a max of 20-30 gallons, so if you had a full 141 gallon tank then it would be another story.
I also think that the 7k lb figure for your boat is a bit on the light side. I know it's not exactly an apples to apples comparison but my 2004 GW 228 Seafarer with a single F225 on it and about a half a tank of fuel was weighed at 5,300 lbs when I launched it on a sling after first buying it. My boat also has a dry weight of 3,510 lbs, so it's almost exactly 600 lbs less than yours, and it also only has one motor, compared to yours with two. If you add up that additional 1,200 lbs to the 5,300 lbs I mentioned before as well as add 100 extra gallons of fuel to fill up the tank, add gear and so forth then I'm thinking you're going to be well over 7k lbs just for the boat. Even more so if you had any fuel in your auxiliary tank. My rough calculation would be about 7,100 lbs just for the boat and a full tank of fuel and nothing else. If you had any additional gear, food, water, ice or anything else in the boat then it would only go up from there. I know that for me, I've got two downriggers, four fishing poles, two 15 lb downrigger balls, a net, smaller sized tackle box, lifejackets, some electronics and other things. But yes, I think you're going to be closer to the 7,500 lb mark with a full tank of fuel and a decent amount of gear in the boat. As for your trailer, I've got no idea, though mine is an aluminum I-beam dual axle trailer and it says it weighs 975 lbs on the registration. How accurate that is? I also have no idea, but yes I think it would be advantageous one of these days to have the boat and trailer weighed on a certified scale.