I have a pair of 25.4mm drops that I've got from an old bike I bought on Yahoo auctions. I guess they're close to 20 years old. Probably 42mm.
Here they are on the frame (at a rather acute angle):
I stripped them off the bike to replace with flat bars. Just a personal thing for commuting as I like to be upright in the city.
They're old, and they're heavy. If you're interested let me know.
The old Cannondale with some old drop bars I'm getting from Wolfman
I am not a Shimano guy but I think the pull ratios on road levers is lower than the MTB levers. Canti brakes and U brakes will be pretty weak unless you get some travel adjusters. watch the diameter of the bars at the stem as well. might be different.
I think your shifters are too low. Move them up higher.
I am wondering, mainly, why did you decide to put drops on this bike?
Stu, congrats on the birth of a truly great looking Frankenbike. MTBs have longer TTs than roadies cause they have straight handlebars, the drops require you to stretch out another 8 to 10 cms beyond straight bars hence the more acute angle between thighs and spine (tummy slap). Looking at the red devil you have spawned I would rotate the handlebars until the tops are parallel to the ground, this will bring the shifters higher and closer and give you a more comfy place to rest your hands. If you really still feel too long between seat and bars take of the seat spin the post 180 degrees and put the seat back on it looks like it will take a reverse mounting. After you've done this and feel like you have learned the lessons of frame sizing and the effects of controls on comfort: come back to us with some suggestions for a road bike. You now have bars, brifters and a heap of other stuff, just need the right sized frame now. Good luck.