How to get either a Pension Book or Pension Number Card reissued from abroad for Lump-sum Withdrawal Application.

I'm coming up on a year since leaving Japan and have started to get my finances in order and get the ball rolling on the lump-sum withdrawal application. I thought I had brought back my blue pension book and notice card with me, but I've been unable to find either. I'll keep looking, but in the meantime, I want to figure out if there is anything I could do in the case of neither turning up.

I found links explaining how to go about getting one reissued, even if unable to apply in person. I do have a tax representative still in Japan, but I'm not certain if they would meet the criteria for requesting a reissue on my behalf.
https://www.nenkin.go.jp/faq/seidozenpan/kisoban/henkotodoke/20120413.html

https://www.nenkin.go.jp/service/kounen/tekiyo/hihokensha2/20150326.html

Alternatively, if anyone knows if the lump-sum withdrawal application accepts anything besides the blue book or notice card as proof of a pension number, that would help open up more options for me.