There is a thread on this but easier just to tap out something I think .............
The water shouldn't be pooling on your bed ends, wax or soap run over the zippers will help keep water weeping thru them.
You only need to waterproof the canvas again, what I used to do was I would wash the inside and out with a mild soapy water, but not soak everything down just enough to wipe the marks off, once its dried off properly and I mean dry I would then rub a stick of bees wax over all the stitching then spray all the canvas with a waterproofing solution, I would buy a liquid for Drizabone coats and put it in a spray bottle and let rip, do my coats as well, give them a good soak, let it all dry and bingo good for a few years, I only ever had a privacy screen around mine and it kept out some gully raker storms, but you will find as is normal with canvas if you lean against it or have some bedding up against it, it may wick moisture and condensation can be a dampner as well.... I wuld stay away from the pressure pack stuff, a waste of money as you need a goodly lot of it.....Some use a silicon over the stitching but I'm old school.
A visit to the saddle shop.
Like with all canvas tents and such, even swags when they are new, ignore the sales pitch that they have been proofed, best to strip them down and give them a good soak in clean water, hang to dry, out of the sun, you will then find the stitching and canvas will shrink up together and close the gaps, then adding a waterproofing agent will improve things........has worked for me for tents,truck tarps and other canvas gear for longer than I care to add up the years.