How to open a 54 year old envelope without damaging it? (DNAF)

Factual Questions
1

I bought a 1959 USA proof set off ebay. Back then, they came in a cello wrapper inside a plain brown envelope. I just talked to my coin guy yesterday, and he said it’s not worth keeping unopened, so I want to open it to check if the insides are really a 1959 set. However, I don’t want to damage the envelope by cutting it, I want to somehow dissolve the glue and open it normally.

DNAF = Don’t need answer fast, it waited 54 years, it can wait a bit longer.

2

You can generally steam an envelope open. Steam softens the glue without saturating the paper.

3

In the movies, you hold the envelop in steam, e.g. from a boiling kettle, until the glue softens.

4

The heat won’t be good for coins and the cello, any other options?

5

Steaming open an envelope is not like it is in the movies. It’s a mess. The paper becomes wrinkled and waterlogged. Opening a 54 year old glued envelope via steaming is likely to significantly wrinkle and warp the surrounding paper. IMO a clean slice with a razor would be much less messy.

Beyond this, possibly a coin maven can answer but re coins does it really have any value to have the manila envelope holding the set remain sealed and undamaged?

6

Coin guy says leaving it unopened adds about a dollar to value.

But having the original envelope, to me, is part of the set.

I don’t buy sets not in the original packaging.

Plus, if the coins aren’t mint in the cello, leaving it unopened assumes they are.

7

My first thought was to search the Smithsonian website or send an email there. Perhaps the Smithsonian Center for Materials Research and Education can help.

Try this - specifically the links for “Paper-Based Materials”.

8

You can try putting it in a freezer. Some glues lose their adhesive power when they freeze.

You can also try lighter fluid (Ronsonol brand seems to be popular). It’ll dissolve many glues. The downside is the smell will remain on the envelope when you’re done.

9

Freezing is probably out, moisture could condense inside the cello. I just went through a bunch of coins yesterday with rust spots.

Lighter fluid is possible, I got leftover ronson brand fluid that has a minimal smell.