Hi LEM,
In step number one I said that anyway the horn will sound if one leg is not down and locked. Recycling the gear is not recommended, I agree, but in any case if you have to perform the go around you will find yourself with Flaps 15 and gear up. Off course You lower the gear with Flaps 5... that's not the point. If you do not wait 3 greens before taking Flaps to 15 You will end up in this situation.
The FCTM states : "Land on all available gear. Recycling the landing gear in an attempt to extend the remaining gear is not recommended. A gear up or partial gear landing is preferable to running out of fuel while attempting to solve a gear problem [...]"
I think we all agree here... but I hope I took enough fuel to perform a go around and make an extra approach with all the things fixed up before landing or starting to burn the MDF. If not, well no need to argue... Vol 2 states
xtinguished
....
- landing gear is down and locked with landing gear lever DN.
And I agree with you 100%, you can land.