I got a vise for Christmas, so I had to clean out under my bench to take the old one off and put the new one on. While I was under there I noticed that the ancient fir that somebody built the frame out of is pretty much rotted through at the back.
I could put the repairs off for another year or two, I guess. Given the strength of that old lumber, I have little fear of it collapsing. I've been running short on projects though, not to mention scrap-lumber firewood, so I guess I'll build it as soon as things warm up in the spring.
I plan to keep the top. It's rough-looking, but it's solid and you just can't get that kind of wood anymore. I might top it with 1/4" plywood painted white to make it less dark...there's 50 or sixty years of oil and grease stains on this one, but the old planks are staying.
For the bottom I'll use 4x4 posts with 2x6 horizontal framing cut into it. I guess I'll likely stick with 4x4 and lap joints for the angle members though...I hate a wobbly bench.
I'm not sure if I want to put shelves and drawers under the bench. The current one is just open with (broken unusable) drawers under the bench, so it's become home to the junk that fits there. Leaving it completely open would give me another six inches for those worthless treasures I tend to collect. Some shelves and working drawers might instill a little badly-needed order though, or at least help to hide the mess.
Oh well, I have about 4 months to figure that part out.