Lump-sum Payment with Lost Pension Book?

Hello all,

I've just returned from Japan after four years working in Tokyo and was filling in the Lump-sum Withdrawal Payment application form for a refund of my National Pension payments when I realised I am supposed to attach a copy of the pension handbook in order to verify the basic pension number. While I know what my basic pension number is, I don't have a copy of the pension handbook having seemingly misplaced it a long time ago. The form says if the pension handbook is not attached they will return the application form. Has anyone else been in the position of trying to get the pension refund without having the pension handbook? Is there any chance of my former municipal office issuing me a new handbook now I'm no longer resident in Japan? Do you know of any other documents I could use to verify the pension number?

Thanks for any help.