Nice chisels - and a good discussion topic -- I have boxwood, laburnum, mahogany, kingwood and ebony from recycled sources in UK (woodpiles and skips, especially when a 100-year-old neighbour who'd been a cutlery canteen maker threw out his off-cut pile). You're encouraging me to get down to the long-planned chisel handle making - afraid I'm not going to make such great own-made blades as DW, but do have a good collection of Ward, Greaves etc to handle.
For the chisels I'm going to whack, I think I'll stick to fast-growth ash and recycled broken hickory sledge handles (maybe also oak - what's the best oak for such?).
Why was beech used so much for English chisels handles? - doesn't seem to take abuse very well - where you find an old user-replaced handle it's more usually ash.
I'm guessing beech was used because it has some interlocking and it's cheap and smooth, no pores or roughness. But it's a bit light feeling for handles if a chisel user is a handle gripper. The virtue of making handles out of something cheap is if they break, you can just make another one, and beech is kind of a dead sounding wood, so it's not loud or irritating to use (which makes it more comfortable on hands in a plane, too - it doesn't vibrate much).
You're definitely ahead of me if you have good salvage woods. I've been buying handle materials generally from places that specialize in exotics or wood for instruments (the wood tends to be straighter in turning blanks and musical instrument blanks). There's a big local exotic lumber dealer here, but they're likely to be higher in price and it's through a high traffic area for me and would be a 2 hour round trip.
as to the oak, your oak is different than ours in feel and appearance. I think if you put a strong ferrule at the butt of the chisel and a good one down by the tang, there shouldn't be much chance of breakage. I like the feel of the end rounded without a ferrule, and a mis-strike at the corners could certainly break something off, but making another one wouldn't be an issue. I had "handle anxiety" with nice sets when I'm not the maker of the tools - if something breaks, then you have a mismatch. If you ever decide to sell the set with a mismatch, 90% of prospective buyers will move on to find a match. I try not to keep tools at this point that I can't feel comfortable using, though, and even if something I make is technically nicer than some of the lower cost options in the open market, I feel free license to use it hard and break it and not constantly look to make sure it's close enough to the center of the bench, etc.
That said, I haven't broken any handles with a urethane mallet, and I like that type of mallet the best as the feel and sound are a bit smoother than a wooden carver's mallet or something else hard. Not a huge fan of the japanese tradition of striking loud handles with steel hammers.
