The most common problem of older Rebels is the lack of proper flotation. You should have at least 10 cubic feet of flotation in the boat with maybe 15 if you sail in open waters like Hugh Western. He describes his experience that because they did not have enough flotation his boat could have been at the bottom of his lake..
Also you read the article that I wrote last year that describes Bill Blaine's experience in rescuing his boat at the Nationals. This article also has some good ideas about adding flotation to your boat. The way to add flotation to a pre 1800 series boat though is to put in severa lbouyancy bags. When you factor the cost of buying fiberglass to put in some types of flotation plus the trouble of doing it using strap in bouyancy bags is a very good way to add enough positive flotation to your boat. Using two part foam that expands can be very messy for the inexperienced person even thoughit is very good when used in a new boat and done by an expert.
I happen to be surfing the web one day several months ago looking for good sources for boat part and came upon a site that has all types of boat accessories. West Marine did not have bouyancy bags but after several emails with there catalog department they were able to locate a source for them. They are made by Jack Holt in Britian and come in various sizes, the one that I got the quote on were all around $100 in price which is a small price to pay for your piece of mind especially if you are sailing in areas like Hugh Western that your boat could sink because of lack of flotation.
The bags are maade of tough and thoroughly tested heavy duty PVC .016" thick and shaped and finished to fit snugly in your boat. Fitting Instructions After checking that there are no sharp points to snag, they should be firmly secured to the boat by webbing straps passing over and round the bag through the positioning loops. Do not use the loops for the actual attachment. Apart from the welded loops each bag has a flexible screw cap and nozzle with a slow return valve to aid inflation
Holt makes many bags and the specs can be see at Jack Holt Buoyancy Bags Bags : The special order department at West Marine gave me prices on 3 different models. . The SB2101 is $73.50, the SB2111 is $103.50, and the SB2802 is $52.00 plus shipping & tax. They can be special ordered and would be ship to you directly. Call West Marine Catalog Dept at 1-888-888-3221 to special order these.
SB2101 33x36x14 inches Triangle shaped Bag
bouyancy 159 kg or about 6 cubic feet
SB2111 16x16x16 inches Wedge shaped bouyancy 43 kg or about 1.75 cubic feet
SB2802 39x16 inches Pillow Bag bouyancy 44 kg or about 1.75 cubic feet
I am guessing on the cubic feet from my long ago memory of geometry. I checked my boat, the flotation bag that was in the front was very close in size to the SB2101. So it should fit into the bow of a Rebel with no problem. The one in my boat said 350 pounds of flotaion and it was wedged between the front deck support and the bow. You should also have a bag in the transom so that if you do capsize the stern does not sink. The one that was in my boat was about 44 by 11 which is a SB2102 which I am sure that they can get. The guy in special order that helped me in locating this item gave me prices base on the sizes that I gave in my first email. I am sure that and size that you want could be ordered if you want a different one than the ones listed.