This I would clean...
I would not call this silver plate...
You are saying this because of the "greening" ?
This may be due to content of silver... or the solder...
Unless it says it is plated... or you have tested it ... I would call it silver... maybe evne just coin silvr.
This is a really cool find...
Clean gently... oil screw with some cooking oil... let sit over night...
DO NOT use a "paste" silver cleaner...
And do not submerge in Tarnex...
You can use Tarnex on a cloth... soak a spot on rag then work the piece... then use another clean water rag to wipe clean...
Do not let the tarnex sit on more than a min... each pass.
Cool piece.
Looking at the photos... it appears to be silver... then it doesn't.
The mark is illegible to me.
And ... I know nothing about their marks for metals...
On thing is for certain... In fact I will bet...
Put this on world wide ebay... will ship to Saudi... you will sell this for a pretty penny I bet...
But... must be working.
OR close.
Oh one last thing... go to nearby jewelry store...
Ask for a "jewelers cloth"... some sell them some don't...
After the above cleaning method... wrap over lighter and begin to rub... clean cracks with your finger nail... etc.
Try to get lookingas mint as poss... an carful with the screw... again do not force it... soak in steps and let sit standing upright with drop of oil on top of screw.
Repeat as nesss... until screw gives...
use proper screwdriver size as well... do not strip it.
IF you can manage to do this... it should be worth your while.
Meanwhile... search similar lighters for a rough value... may even find exact one.
Ok now... ball is your court.
Worst case scenario... the screw is "set" and not silver...
Still list it.
Tis silver...
Polish away with cloth only now after looking.
leave SOME tarnish till it looks like the one in the pics...
scratch the tarnex...
they seem to like these looking like that a bit.
Btw jeff I am a BIG advocate of NOT cleanin antiques...
BUT for certain thigs like this iyem... and Jewelry... yes.
Personal items do better with a cleaning.
ARRC, you nailed it ! I was going to say this looked liked "trench art" something handmade by a soldier or P.O.W. After reading the article, I see it's similar, still handmade, but looks like they could set up a little shop with more resources than a soldier or P.O.W. would have. Search "trench art lighter" to see more handmade lighters made in world war two.
I don't know about all the polishing, but you can replace the rusty mechanisms and get it in working condition. Should help the value a great deal. Nice lighter !!