Originally Posted by LeeG

All right! That's great. The cheapest and lightest way to go is no front rack with a compression sack bundle containing sleeping bag with tarp/whatever strapped under the bars. Maybe 5lbs of stuff. Then a cheap rear rack with top plate as fender with one or two dry bags strapped on top. In between those two loads well secured on the frame or seatpost are infrequently used but necessary items like tube or tools. Maybe a "gas tank" type bag on the top tube near the stem. Maybe a spare bottle holder could be attached behind the seat or the spare tubes/tool bag under the down tube. Basically make it so that if you and the bike wipe out everything stays attached and if you need to remove anything it just takes a few seconds undoing buckles or straps. Be careful of single point failure attachments, in other words if one buckle/strap/bungie fails the whole mess doesn't fly or go in the wheels.
I think you can get close to 20lbs with that set up and the nice part is that it will make for a solid bike load that moves as one on twisties and descents as well as slow going up hills and also won't overload skinny tires.

If you HAVE to have panniers you might as well go the new fork route with low riders and a fast 28-32mm tire, there's more to gain for rim protection, comfort. Not sure whether your old front brake would be compatible with new fork and rim location. It would be a shame to change forks for more weight but be stuck with 25mm tires for it. You can have some minor changes in fork dimension, length, offset without it being a problem. I had an old Italian road bike with steep angles, Columbus tubing and very stiff fork. I changed out the fork from an English road bike that was a more comfortable ride and had a blast. Nice thing about those old bikes is that a fat 28mm to skinny 32mm could often fit in there.

given the size of your load a trailer isn't worth it, 10-15lbs of trailer to carry 20lbs of gear doesn't make sense