Thanks for that. I hadn't considered such possibilities 

I’m old school generation war memorabilia collector, competitive shooter, range officer, and match director from U.S. deep southern cornbread born raised who has closet full of trophies since mid 80s long before smarter mobile phones than I existed, lol. I spent my childhood and adulthood working daily and help take care of my elderly great grandparents, grandparents, mom and dad before they crossed over to our Lord and Saver! I realized at a young age every time we lose a elder family member we lose a World Historical National Library! Beyond all doubt if we don’t fail on our responsibilities as parents, grandparents, and great grandparents to pass along our past elders experiences to our future generations, then only then have we achieved success! The countless hours I spent from childhood until my last elder family member passed away years ago for my only son to learn is truly endless valuable knowledge to pass onto to our future generations!  I do have several collectibles I’m seeking knowledge for!  I’m NOT here to take advantage of anyone as we all have our own crosses to bear in this life or the next!  “Those who don’t learn history tends to repeat it” - Benjamin Franklin    Thanks for your Time and Consideration, LeadSplatter

The top photo shows a better picture of the liner, you'll notice that there is no joint in the back of the liner where the liner bridge joins, which would have been stitched together.

Practice bomb.

I agree with Marshallj,,   Some type of drop tank..   Leigh 

My guess is that is an external fuel tank. 

Many years ago a friend and I stumbled across this and, in retrospect, rather carelessly took this pic. Would anyone be able to shed any light on it please? Thanks 

Hi Bill, was able to find 1 additional pic of the liner. Not sure it will help much but I'm including both for you.  BTW, it sold for $350 (fortunately not to me)    

I'll see if I can dig them up. I think the liner appears to b pigskin (don't have the helmet so no smelling). My researching noted IJN helmets are cowskin & IJA are pigskin. The repainting brings up a big stumbling block for me. I've seen a helmet shell on Dan's site for ~ $600. Paints original - kinda infers that installing a liner & tie chinstrap is ok? Or hands off. One additional, was unable to send you a pm. Sure I got it wrong cuz couldn't get it to send     I'll see if I can dig them up. I think the liner appears to b pigskin (don't have the helmet so no smelling). My researching noted IJN helmets are cowskin & IJA are pigskin. The repainting brings up a big stumbling block for me. I've seen a helmet shell on Dan's site for ~ $600. Paints original - kinda infers that installing a liner & tie chinstrap is ok? Or hands off. One additional, was unable to send you a pm. Sure I got it wrong cuz couldn't get it to send   I spent time over past few days looking at Dan's helmets & those in this post. The anchor is crooked & its the same color as the repaint. According to Dan's info the emblems tend to wear faster. Also liner is the wrong type of leather. Hey could you pm me?  

IMHO the anchor is bad, and it appears to have been repainted over the chips of the original paint, the shell might original.Can you post photos of the liner bridge at the back of the helmet? Does the liner smell like leather? I would pass on this one but that's up to you.

Thanks Bill for following up. I didn't pull the trigger on this one. I'm only gonna buy one Japanese helmet & don't want an almost right or fake one. Just from the photo I had concerns about the Anchor emblem & the liner looks off. What did you see?   You've got some great helmets Titus 

Sorry, but I don't like anything about this lid, I think it's bad.                           Bill