My Ribtec was in a similar state when I bought it, although wasn't actually leaking.
Look like you might already be doing it, but you should be able to prove/pinpoint the leaks using copious amounts of fairy liquid/water to create a nice foam to display the escaping bubbles!
Because my tubes weren't actually leaking, and other than certain areas on the very top, were in excellent condition, I decided to go for some recovering to begin with. Even if that only makes it last a couple more years before a complete retube, I decided it was worth it.
Pics from my before and after are here: Wear patches for 9m Ribtec
. I had my bow (the worst bit) professionally done by Scott at RibRepair, as I thought getting round the curve and keeping it flat would be beyond my skills!
Now looking at adding some Treadmaster wear patches to some of the smaller, flat sections myself over the Summer when the sun's out.