I think it is very close to 200lbs. Years ago we weighed the heart, lungs and liver of a deer that was supposedly dressed out and the deer went from 216 to 195 lbs. That was 21 lbs. The stomach and intestines had to weigh another 20 lbs or so along with a lot of blood.
What interesting about the formula theory is the overall weight has variability. Do the guts have that same variance? My guess is a 200 lbs live weight deer's guts would weigh approximately the same weight as a 250 lbs live weight deer. Thinking a pre-rut / post-rut buck would have the same guts weight.I just looked at about half a dozen formulas. All but one says to multiply by 78 percent. So .78 time 250.