Somewhere I have this exact mold buried away. Today's version of the same bait has some detail to it but basically the balance is about the same and these are real workhorses at times and are fairly easy to master. That Ultra Minnow vibrating lure takes a bit of getting used to in how to work it but when a guy gets the hang if it, it to is a real catcher. I fish the Ultra blades on Lake Superior and the Lake Trout don't seem the least bit happy about how well they work.
Outside of the laker fishing I find that blades have a couple windows where they work very well but outside of those windows they can really drop off in productivity. Periods during the spring and fall will get worked pretty good with blades. When I still ice fished on the big river blades were always along for the ride and caught many, many nice walleyes, especially late day and in shallow sandy water. Areas of shallow sandy shoreline right now in the high and hard running Mississippi River would be well worth the effort to work the blades.