So this is what I remember:
A young woman’s husband/father is murdered by a dismembered hand,which disappears, through a portal of some sort. The police doesn’t believe her and she has some time to prove her innocence. Her friend and another guy find a way to open the portal and go through a series of time portals, landing in different times. One of those being where the other guy gets mauled by a beast of some sort and the friend throws a vat of acid on him and then throws salt on the now exposed ribs (this is shot in black and white). The other guy does at some point and later the friend realizes that they only have enough time travelling juice for 2 trips, so sends the chick to the next portal or whatever, where
(possibly distant future) humans have discovered how to animate body parts and she catches hold of a hand, gets back just in time for her trial, shows the zombified, animate hand to the court. Court is stunned and she is acquitted.
As the proceedings get over, a postman meets her outside the court and hands her a big box, which looks like its really old. Apparently was mailed by the guy who was left behind and sends her the time travel thingy and she opens the portal to go to him
Champion!!!