Dont Know What To Do With Box Of Airmail Envelopes

I have come across a shoebox size box of envelopes, all airmail from various countries, in a box I brought from an auction. This isn't something I collect and know nothing about.
What I have looked at so far seems to be postmarked around 1970 and all relate to a textile manufacturing company in Manchester UK which is no longer there.
In the past if I get any first day covers in these boxes I remove the stamps for my collection / stock books unless the cover is worth keeping but I know nothing about airmail. Most are the red and blue edged, very thin lightweight almost like rice paper varieties, the rest are a mix of envelopes with company logos, addresses, some have postmarked from both countries. It's very mixed as there are hundreds, the box must weigh two or three pounds.
Initially I was going to just strip off the stamps after looking at an online auction site and seeing a lot posted but not selling for anything but I don't want to make a schoolboy error and trash any true value or what someone else may get enjoyment from.
Any advice would be greatly appreciated.

Air-mail stamps are no different from any other postage stamps. If you're intending to sell, I'd leave the covers intact, sort into country or geographical groups and put them on ebay in decent-sized lots. It's likely that stamps from this period, if removed from the covers, will be worth even less. If you want the stamps themselves, either soak them or neatly make a rectangular cut around stamp and postmark.

The stamps themselves are not airmail, they are regular stamps. One I have in front of me now is from Bermuda with a 1'6 constitution of 1968 stamp on a come to Bermuda the isle of beauty post mark and via airmail stamped on the envelope with the red and blue surround.

The advice is the same. If you want the stamp, but don't want to display a whole cover, either soak it or cut a neat rectangle around the stamp and cancel and mount it on a page after your other Bermudan stamps or place on a stock-page. If you don't want it, leave the cover intact and sell as part if a Commonwealth, West Indies or other combined lot.

Thank you. I suspected they would be pretty common but when you think back to when you first started and the mistakes you made I just wanted to check and I have no experience in airmail envelopes like this despite many years if collecting. There are many on ebay and very few actually have bids on them.
I have covered the cost of the auction lot with what I have removed for my collection so I'll soak the ones I deem worth keeping and donate the rest to a charity in town, I don't have the space to collect covers unless they are going to hold a worthwhile value.
Thanks again

Just a thought... might there be someone who collects Manchester postal history who might be interested?

I think it might be interesting to a Manchester collector only if there are postal markings pertaining to Manchester, particularly if these are covers from the last 50 years or so. As suggested, breaking it into related area groups makes it more appealing to more collectors. It is work, but I think fun work. Then you can go buy stamps with the proceeds.