I agree with Bordercollie, and since you already have the carb off you might as well clean it. You didn't mention whether you stoped the gas line from the carb to see if it would start once the flooding was controlled.
For reasons I don't know, sometimes I find spark plugs fire great but still don't work. Dunno why, so I would definitely just replace the plug (s).
Generally carbs are all the same, and simple at that. Since I suspect the problem is at the initial intake float needle causing flooding (indicated by the gas running out the overflow tube) I suggest you hold the carb upright and blow into the gas line connection. Probably most of the gas ran out during the process of removing the carb, or while turning it over to admire it. So, when you blow it should let the air thru. Then, turn it over and blow. You shouldn't be able to blow thru it upside down. If you can...that indicates the needle is indeed stuck off the seat. Although I would go ahead with the thorough cleaning of the whole carb, you seem reluctant, so you could simply remove the bowl, then the float pivot pin, then the needle should drop out. Clean that orifice and put the float back in so you can do the blow test again. For your comfort, that might solve the problem without you having to go further. An engine will usually start with the needle jets turned out one and a half turns, then you can dial it in. That part won't be an issue, however, if you don't clean the whole carb.