Organs with clear demarcation have a definable weight with + - figures like liver = 1.5kg in humans + - 60gms. Hypothalamus in animal, including rats and human is an area with complex merging tissues. The reason you wont find a figure for that. It depends where the dissections were made. Hope it helps.
I agree with Abdul Mannan Baig; also, you should specify age and gender to get a proper answer. I work with adult male Sprague Dawley samples from SN and CPu. If you need those values let me know.