It's a Johnson (with the older- looks 1970'sish- Johnson and seahorse logo on the back of the cowl), says "Javelin" on the sides of the cowl, with "One Hundred" in script writing on the sides of the cowl too.

Here's what the little plaque said:

Model #: 100TLR79S

Serial #: J5143861


Also, is cleaning up/rebuilding the carb easy enough for the average joe to do (who is reasonably mechanically inclined) with a kit? If so, where do I get a carb rebuild kit for my engine? My local Johnson dealer?

And just to make sure I have the carbureator located right: If you're looking at the top side of the engine, you have the spark plugs and the propeller at the top, and the carbureator is on the very bottom closest to the stern of the boat, where the oil pan would be on a car engine. I traced the fuel line into the engine, and it ended here. I'm assuming that this is the carbureator.

According to my book, you have a 1979 model 100hp Johnson motor.

Thank you sir. What about the carb rebuild? Since it's just been sitting around for a couple years, I'm assuming that it needs a rebuild.

More than likely it will need a carb job, go to your local dealer for your parts, he should have them, if not can order them, I would also put a new water pump in too, you should consider letting a mechanic do your work if you are not experienced in working on them or at least try to get someone to show you how to do it, the water pump can be a daunting task if you don't know where to look for things that have to come loose to drop the lower unit.If you were close by, I would help you out.

Yeah, unfortunately I'm about 20 hours away in Kentucky. Oh well, I'll just take it to a mechanic. About how much should I expect to pay for a carb rebuild and a new water pump?

It is hard to say for your area. Each shop may have different shop rates per hour. I am gonna just GUESS now, no more that $350.00 for all the repairs, water pump, service lower unit & rebuild carbs, this ONLY a GUESS on my part now! Sounds like you have a nice gift though, it will not hurt too bad to do what is necessary to get it on the water, the price was right for the boat & motor!Good fishing, God Bless ya & be safe!