You are taking a HUGE risk to your VHS deck. As Fiddler points out, the heads on a VHS deck are very delicate. Unlike audio tape, VHS tape wraps around a head. When you add splicing tape (please don't use anything like scotch tape!) you are adding to the thickness of the VHS. That is very likely to get wrapped around the heads and you will end up with a boat anchor instead of a VHS deck.

I would strongly suggest looking for a DVD of the tape you have in question.   Try someplace like Elderly Instruments.   

The alternative is to roll the dice, but be prepared to spend $$$ for a new VHS deck and the loss of your VHS tape.