Switzerland : Pictures Of Varieties

Hello
I would like to know where ( in which catalogues, magazines, publications etc.) I can find pictures of varieties of stamps ?
Of course I am not talking about those ones which are already shown in the Zumstein or Michel specialized catalogues but about rarer varieties.
Example:
Now, I am searching the picture of the variety of the stamp Pro Juventute 1939 Zum. 91/ Mich. 361
In the "Zumstein spezial Katalog" it has the nr 91.1.09 or 10. It is not mentioned in the catalogue Michel.
Where can I find pictures of such varieties? In which books, publications ....? Can you advise me where to search ?

Thank you

To answer your question -------very few varieties are listed that are searchable on the internet . Your best bet would be to find a specialist who collects them and ask for a scan to be posted for you .
There are millions of varieties in stamp collections around the world, the internet is too new for any kind of reference source of all . Try some of the specialized society web sites .

I am talking about variety which are mentionned in the cotation catalogue, with a price, but which have no associated pictures in them !

Of course, I am also searching in philatelic clubs, but maybe somebody here has good links for that concerning Swiss stamps.

PRIATEL ----Since I don't know what the variety is {I don't have a Swiss specialized catalog} can you describe the variety and maybe someone or I can search around and help you .

One possible approach is to scan the stamp variety and then do an 'image search' with Google or TinEye.
Don

Priatel, I think one problem would be the fact that 91.1.09 and 91.1.10 are both missing color varieties. That in itself would not do much good in a black and white catalog? On the former number the red is partially missing. On a stamp that is mainly red it would be easy to see if part of it is missing. By the way, the catalog I have is a Zumstein 2000 and it shows the latter variety ( 91.1.10 ).

Peter

Here the stamp I have between 2 standard ones:

That looks more like a changeling than anything else. Look at the cancellation, it is also faded somewhat. Priatel, I think you can send a scan of this to the folks at Zumstein and ask for their opinion!

Peter

@Peter4522
I don't think so.
I have another stamp with similar properties ( but there is no vatiety mentionned in the Zumstein catalogue)
It concerns the Pro Juventute 1938 Nr 87





And you can see that the cancellation is not affected.

Also looks chemically altered to me! Take my suggestion and send the pictures to Zumstein!

Peter