Mills antique slot machine cashbox liner and noise deadener

Description

We are owners of multiple rather large 300 to 500 unit & larger storage rental unit facilities in several states.  Unfortunately on occasion people don't pay their rent and abandon their processions.   By law we have to make a concerted effort to find them & we do try but after several months we simply hall away the contents to the dump, give it to Salvation Army, or if something appears to have value, we list it on eBay.
We are in the storage facility rental business wanting to get the unit back up for rent and not antique dealers so our knowledge isn't all that much.  We describe what we see but please don't ask us for more like age, how it was made or of what made from, country of origin, or if good to eat.   All our sales on eBay go to our favorite charity that helps battered and abused women after
eBay takes their 20% + commission & fees.
We keep none of it.  And no, we don't have live sight unseen auctions like on TV.  If you buy into that we have a bridge to sell you in Brooklyn or a time share apartment on the Afghanistan/Pakistan border.  Lovely apartment above a great deli with topless waitresses.
We don’t know how desirable these are but there are “purists” who want their antique slot machine exactly as it left the factory back in the day.
We found a small quantity of these on a heavy thick stock that was meant to go inside the cash box of any Mills machine and all of their machines came with this.
One old timer we talked to said it actually had a functional purpose more than anything else that most might never think of.
The sound of a coin falling into a cash box was not a signal they thought was a good idea to send to the player or anybody for that matter.
The thick card stock prevented that and once the cash box bottom was layered with coins, the following coins fell on others and the sound was deadened.
Amazing all the thought that went into taking the money from anybody.
We’d like to keep the cost minimal for any buyer and send in an envelope.
We would gently fold it but try not to crease it.
If a slight crease was there upon arrival from the post office, a clothes iron would simply remove that.
Or we can put in a Manila envelop with stiff backing to get the tracking & send for .20 if the buyer so wished but we think it would be a waste of money.