If you are the only person to receive this level of payment then it is highly unusual.
Precedence is very strong in this area so if you take a case you have a v good chance of getting an equal package.
You would need to contact the WRC, I don't think a solicitor will be of much benefit considering the cost.
Advise the company that you intend following the WRC route to get the same package as the others - if they are winding up the company ( legally closing it ) they won't want this hanging over them.
See below for a taste of how the WRC views the reasonableness of ex-gratia settlements. There are industry norms that create precedence but in your unusual case your company is not following it's own norm. Something doesn't seem right.
Anne O'Connell Solicitors, AOC Solicitors, Solicitors in Dublin, Specialists in Employment Law
aocsolicitors.ie