My dad died last year and left a will which wasn't written by him and the witnesses one being dead and the other said he didn't remember signing a will for him the handwriting definitely isn't my dads but the signature is.my dads he was a nasty man who abused me so when I was 14 I left home never to visit him .he left his house and money to my younger sister leaving out myself another sister and my 3 brothers the will was written 16 years ago and is outdated .we have a solicitor who says it will be an uphill struggle and talked about probabilities .we also don't know what else my sister has claimed for as she won't show us his final bank statements.I am in England

Your solicitor is right - it will be an uphill battle, and probably will cost you more in legal fees than 5 of you might each get (you don't say how much money he had).
The fact that the will was not in his handwriting is not meaningful, nor is the fact that it is 16 years old. There is no such thing as outdated, unless it doesn't cover who is next in line if someone mentioned in it dies.
Who is executor? Your youngest sister, who was presumably living with him?
His bank accounts will be frozen during probate unless she had joint accounts with him. If you aren't in the will, there isn't anything you can do about them.

my dad died last year and left a will which wasn't written by him and the witnesses one being dead and the other said he didn't remember signing a will for him the handwriting definitely isn't my dads but the signature is.my dads he was a nasty man who abused me so when i was 14 i left home never to visit him .he left his house and money to my younger sister leaving out myself another sister and my 3 brothers the will was written 16 years ago and is outdated .we have a solicitor who says it will be an uphill struggle and talked about probabilities .we also don't know what else my sister has claimed for as she wont show us his final bank statements.i am in England


I agree with the solicitor - if it's a valid Will (and it doesn't need to be written out by your father, signed, witnesses are in order), it's a valid will.

As I understand it your father was a "nasty man" who "abused you" - you left home at 14 (I don't know how long ago that was) and never saw him again. He left "everything" to one of your siblings and nothing to the other siblings and you.

Why would you expect to inherit from him?

... the handwriting definitely isn't my dads but the signature is. ...

All that means is that someone hand-wrote it instead of typed it for him. There is no problem with that.