Lithograving: I do not collect Japanese stamps, so am unaware of precisely what might have been issued using this process. I suspect not many. I entered "Japan stamps tonal engraving" into Google and found....
"1 November 1971, Japan Government Printing Works Centenary. 'Ryu-ko zu (Dragon and Tiger)' 1895 by Hashimoto Gah#333; ( 1835-1908 ) tonal-engraving. These stamps, a set of two, were issued to celebrate 100 years of stamp and banknote printing. So, they are naturally representative of what they can do best for this kind of process. Surely they took time to do the details of the waves. I have to look up what 'tonal engraving' could be – if I magnify, it seems the tone is made by lines and dots together. Paper as well, seems a little special for this printing."
The wording for the above issue is from the website and included scans, attached. If you download the enlarged portion and view, the lines and dots are quite clear.
"JAPANESE THEATRE SERIES POSTAGE STAMPS (III) "BUNRAKU"
Date of issue: 01 March 1972 - the 50 yen "Awa-no-naruto" stamp (of three - the other two are gravure only) is tonal engraving, dry offset."
"JAPANESE THEATRE SERIES POSTAGE STAMPS (IV) "NOH"
Date of issue: 20 September 1972 - the 20 yen "Tamura" stamp (of three - the other two are gravure only) is tonal engraving."
There are no other mentions of tonal engraving in relation to stamps online, so maybe this is all of the issues. The date ties-up with when the invention was patented. Hope this helps. GLENN