I’ve looked through numerous catalogs, consulted a friend that runs a hobby shop and so far have come up empty. I have not been able to find plastic or wood models of any ancient Egyptian vessels. At this point I can only recommend that you might consider scratch building one. There seems to be reference on several versions, with Chop’s barge being the most covered subject.
The fist problem I can see is that power boat models tend to stop at the wrong moment just when they are out of reach so you will probably need the use of a dinghy and Evan a small outboard, along with all the appropriate safety gear. This is something not to be taken on lightly! I suggest you start by reading a few magazines and pick up some ideas of size and shape of hulls etc unusual weed pipes.
You will probably be better off building a boat with a weed eater petrol engine, one that has already been converted to model marine use. This will save a lot of work for you. You could try a visit to your local model store and check out the prices for some of the models that you are thinking of getting. There are other items to consider: – petrol tank 2-3 pints, fuel and water pipes, shaft and props couplings rudder, water scoop, and exhaust pipe and outlet. Last but not least the radio 2/3 channel on a suitable frequency to suite your state, check at your local model store.
Me cruiser used 5 different gear ratios in 1983 on the Alpha not including counter rotation models. I have no cross-references for that serial number to which gear case. If you have seacocks on the through hull connections then sure you can do it in the water. Most technicians routinely replace the seawater pump impellers with the boat in the water. And yes, the closed cooling models use seawater to cool the heat exchanger and elbows. Also, the heat exchangers have end caps, which can be removed, and can be cleaned out.
Opening the fuel jet on an already beleaguered engine might cause more harm than good results, or bring about costly repairs or its early demise. Changing the prop’s pitch & diameter will give you an advantage when starting up, but don’t be disappointed with the top end performance. You need to experiment with a few props to see which one actually works best for your purpose. Most marinas have used/rebuilt props to offer for testing, before making a purchase.
A 5′ diameter tube is quite huge. A larger, wider water tube may be a partial solution, but keep in mind, an expanded diameter means more friction area, which in turn causes resistance – versus disbursing weight load over a wider surface. And, there’s no need to switch boat models, yours is just fine for all purposes described. Test some props first. It might surprise you, and the cost will be warranted. Reduce the diameter but increase the pitch within the engine manufacturer’s parameters.
Replacement skegs are available that can be welded on. Most prop shops do this kind of work. Another option is a “Skeggard”. This is a bolt on skegs that slides over the old broken unit. They come in a variety of models to fit most outboards and I/O’s. There is a simple bolt on. I do recommend using some 3M 5200 Fast Cure sealant when you install it. It won’t look like new skegs as it is polished Stainless Steel should do the trick. Available through most marine supply stores.