Question marks probably indicate uncertainty. The table you referenced contains links to more details by year. Lynn probably followed the 1981 link to a s/n with one fewer digits. The s/n you provided is a 83 model 600 with 22 inch seat tube. So it's not a 24" frame but the stand over height will be approx 32" as advertised- maybe a little under. Assuming the frame is in fact a 22" size that's about right for a 6 foot tall rider.