Model 229SRT means that the blade was 22" long by 9" wide, it had a single raised rib running down one side of the blade only and the grip was a "T"-grip. It was actually one of the less common Clement models and was more or less technically aimed at the flatwater sprint boat paddlers. The more common, somewhat more general purpose paddle in that series was the 268DRT (26" by 8" blade, Double Rib, T-grip). The double-rib just meant that it had a raised rib running down both sides of the blade, which made it slightly heavier and stronger.
Your SRT is actually designed to be used with the ribed side as the non-power face and the flatter side toward you. That way the rib helps keep the blade from bending.
The blade, as I remember was two laminations of narrow strips (spruce) sandwiching a thin layer of hardwood veneer (birch or maple, I think). The tip areas on these models had an additional thin slab of veneer on each side making five layers down there. This was all done in a blade with a total thickness of about 3/16". The shaft was two layers of spruce sandwiching a slab of ash.
Clement paddles were common in high-end shops through the 1970's and a paddle like that one sold for $30-$35 or so back then, which was pretty good money. They were light, reasonably strong and very nicely made. There were quite a few models in the line, divided into two basic categories: those built similarly to your paddle and made in various shapes and sizes and a somewhat less expensive line where the blades were made from parallel spruce strips, but not laminated in layers with veneer except at the tip. Their blades were more similar to solid wooden paddles in thickness and they had rounded tips and pear grips.
The blanks for the various models were glued up from all the required pieces and then the blank made two or three passes through the same type of gang-saw carving machines that were used in Scandinavia to carve wooden cross-country skis and danish modern furniture. In a few seconds, it went from a bunch of glued-together blocks to a carved paddle, ready for final sanding and varnishing. In an industry where nearly all wooden stuff was mostly hand-made, this was pretty revolutionary - kind of like modern CNC machine work, but before computers and purely mechanical (and expensive to tool-up).
In general, they were excellent paddles and very light, though maybe not quite as heavy-duty as other brands. In the US, the exclusibe distributor was a guy near Green Bay named Ray Dodge who was kind of cranky and hard to deal with. Ray had a big sailboat, but I'm not sure he was a paddler. In the end, I think the cost of production, the limited number of folks who actually have a use for a canoe paddle and having to deal with Ray, combined with the recession in the late '70's (which really hit outdoor stores hard) spelled the end of Clement paddles.
It's a good one though, hang on to it.
