Here are a few pictures! I always keep airplane gas in all of the small engines you see here, as well as all small engines and motorcycles that I don't use on a regular (at least weekly) basis. The reason is that airplane gas is specially formulated not to gum up carbs and fuel systems or otherwise go bad when sitting around for a long time. It costs a bit more, maybe twice as much as regular gas, but it's certainly worth it and available without too much trouble from your local airport.
Here are some pictures of a 20' trailer I built recently. It's mainly for carrying 20-25' pieces of steel, so it's not designed for a whole lot of weight and couldn't carry a tractor or anything, but I have already found it to be useful for the purpose for which is was designed. I have hauled 30-foot telephone poles and a 35-foot metal light post on it with proper weight distribution / balance. Sweet!

Here are the 2 desulfators, close up.

Here are the connections to the batteries. You'll notice the little toroids, made with red enameled wire wound around little donut forms that I got off of some computer power supply leads. They keep the pulses from the desulfators isolated from the power supplies which are charging the batteries (and running the desulfators). There are actually dropping resistors between the power supplies and the batteries too, but the toroids can't hurt and are necessary if/when the dropping resistors are taken out, as the capacitors on power supplies present a short circuit to pulses such as those the desulfators put out.

The schematic and discussion of these desulfators can be found either here. If you build one, remember the error in the original article about the capacitor having the wrong value printed: the .022uf should be .0022uf instead.

These are pallet racks I got and put together in the airplane hangar to store my "treasures" on. There are a couple of riding mowers, some forklift battery chargers, some go-karts, Elvis's C-85 airplane engine, some spare seats for my van, and miscellaneous large odds and ends stashed up there.

This is the power plant I made out of an old military surplus alternator. It puts out 115V at 22 amps. It's made by "Island Electric" and has 8 (!) brushes inside. I've put a 20-amp circuit breaker on it and an 8HP Briggs & Stratton engine and it seems to work fine.

This is a 2500W power plant I bought for $100 from a friend. After 5 years of sitting around it started up just fine after cleaning out the gas tank a bit. Amazing! I fixed up a governor on it and it works fine too.