Help identify the genuine coin or not? value of the coin ...

Weight 4.95g,
diameter of 23.6mm,
thickness of 2mm.

If it is genuine, then that's a very nice coin indeed, and I would wear gloves when handling it.

Unfortunately, I don't think it is. I can't seem to find a great deal, but from what I've read, the 1927 Irish Free State Shilling has medal alignment and is 4.67g. See here (Page 4 labelled IR005)

(Edit) Not much info here either http://www.ngccoin.com/price-guide/world/ireland-republic-shilling-km-pr6-1927-cuid-32032-duid-93937