Probably not but it's been in that oil paper for all of the 25 years I've owned it and I bought it that way in a trunk of stuff. The previous owner was the 2nd owner (son) and he told me it was always like that as far as he could remember too when his dad showed it to him. It has done the job keeping it fresh I'd say. I dont think Ive actually had it out of the paper until today in at least 10 years.
Vic, that is a nice launcher. Nothing can be said about the wrap since the japanese were too inconsiderate to mark and proof the paper for us collectors. This is the more common launcher with the "53" being the coded date for 1943, and the character "ni" (above the 53) is the secret ordnance code for nagoya. They made about 17k in 1942 and 32k in 1943 when production ceased. They came in a tan/khaki canvas pouch with "lift the dot" fastener with a wrench to remove the barrel.
I have a type 99 rifle sent back in a wooden shipping box made by the GI who sent it pack. It's packed with that brown oily paper. I cant say if it's of US or Japanese origin but the rifle came from Leyte and he stuffed a lot of it in the box so it must have been easy to get.
I posted this picture a few months ago. Here is my T100 and the rarer variation of the T2 launcher. Only 7 of the T2 variation w the Nagoya arsenal mark are reported in the book titled, Imperial Japanese Grenade Rifles and Launchers. I contacted Greg B., one of the authors of the GLauncher book, a month or so ago. He stated that he had acquired one for his collection since publishing plus this one brings the total to 9 known. I'm sure that there are a few more out there.
Is that type 100 painted black ? I also own a Nagoya marked type 2. Uncertain if it made it into the book but I did send Greg the data. Vic, here's a page from the book showing pouch http://www.tekidanki.com/book/
WWII, I also have a Nagoya 100. I disremember if the things are numbered, but when I pull it from its salt water storage tank I'll try to see. I use the salt water storage method to give metal items character (ask the mutt). Rifles I sold him had not leaked oil through the shipping box, so he started moaning and groaning!
For those of you not in possession of the Babich book the Nagoya 100 was the only one specifically made for the 99 Arisaka. Book is a little pricey, but a worth while purchase.