As far as last/shape, I actually think they're almost identical to my Cliffords (also in Oak) which led me to worry about redundant crossover (why have 2 pair of essentially the same shoe, one as a shoe and one as a boot?). Obviously, I talked myself through it - plus the balmoral shoe vs. blucher boot helps distinguish them a bit too. I'll also note that the medallion between them is different (the Clifford sports a traditional [ahem] "cock and balls") which is nice so they don't have the same toes.
If I remember correctly, the Ludlow are on 348 (which is probably the most popular/common HG last). Sharp boot and I am still sad BNY did not have my size. Wear in good health.