it also depends how much the lost during drying, just try not to let them dry out to much before doing the cure, they dry out to dry if left long enough and you will lose a lot more weight that way, so keep a good eye on the drying process but im sure its old news and you know all this,
ive found the 70% loss in weight from wet to dry a bit off, sometimes it can be around 50% but ive not had any buds that lose 70% but then im not checking all my buds, i just weigh the biggest buf and then when its dry and find around 50 to 60% at most is lost during drying process, also some strains have heavy dense buds and some have light fluffier buds, so until its dried and cured you will only be able to guess, but yours look nice a dense so im sure you will be very happy with the harvest,
id be very happy if it was mine,