I would disagree with Cephus
I see that there are a lot of very nice stamps especially mint ones. I don't know about retail value but several are have catalog values of 40s 70s and possibly even higher $.
I recently sold a small lot of average Japanese stamps on
ebay. Surprisingly I got lot more for it that I was expecting with lots of bids. I guess you never know what is popular on any particular day.
kaigunair
You may be able to find Scott catalog volume 4 countries J to O in your local library. Or, if you use torrents, download one.