jdm

Vise grips are mentioned, if you want to do that or any other brute force method that is, of course, entirely up to you.

If the pins are covered, being invisible to the eye there is no specific tool. One would need to precision drill and destroy the cap, then replace it it and polish together to the link, or fit a collet and leave the hole being visible.

With browser copy and paste. Go to desired topic or website, click address bar, copy. Then paste into any other topic or whatever else.

Feel free to link it anytime. Also, moderators can make it pinned and/or starred, so it stays on top of the topics list.

Welcome, and good luck!

I don't know of a book but you can get a starting point by the video below, and the many, many topics on this forum that you can find using the search box top right.

As mentioned you would fit as was originally done with a clear cement (Ultra Violet curing type, or not), but you can also use a nylon gasket, with a mineral crystal IMHO that's more practical.

I was thinking that with a domed crystal it may be needed to use a concave top die to avoid the risk of breaking it. It may or may be not in the set that comes with a press. After all it can be more expeditious to get the crystal then bring it to a watch shop for installation. Some battery change booths are good and equipped for that.

I must say that with the better quality ones mentioned in the topic above I could open bazillion watches and a Swiss made one would not make any difference. The real issue comes with extremely tight casebacks for which you want a bench opener, or at least an excelled holder block and a two handles opener.

I think that can be caused only by the square pieces that hold the bits to be different height, and/or the bits themselves to not be accurate. It should be correctable without any special tool. Check that the square parts mentioned above are assembled correctly, that is they are inserted on the same turn of the threaded bar. Also, avoid tightening their knobs, so they can align better.

Check this thread:

No offense but I believe than posting pictures helps others help you. Hope you won't be bothered by that .

Same, for a reasonable price: https://www.aliexpress.com/item/2029153808.html BTW, my Chinese 5700 doesn't any of the issues described by the OP, and works perfectly. However, the casting isn't perfect, and the some of the bits sent were duplicated. I remedied that easily on the lathe,

Then as a collector you should own a book, or know well the websites to compare the reference and visualize other Deville front loaders - most often a simple Google search is enough. Since you mentioned the worry of having being scammed I understood you was worried about authenticity, for which as logic dictates, pictures are absolutely indispensable.

You are asking for authenticity opinions, now beside that this is the wrong section for that, you really, really have to post pictures if you want meaningful replies.