Austria 27-30 And 34-37 (Scott)

These four stamps have been in my collection for almost forty years and I suspect that they are Scott 34-37 but how do I prove it? There are no duplicates available to compare them against.
Thanks in advance.
Lizardly,
halflizard

If you have to lead a fish to water, it is probably alreasy dead and you are wasting your time.

There's usually a noticeable difference unless you have one with significant plate wear.

Can't help you unless you post a high resolution pic.

The 2kr yellow (#27) is very difficult to tell. Try to make that scan with very high contrast.

Thanks for your help. I obtained a picture from a friend but can't seem to find the small camera icon to click on in order to send the photo. What do I do now? I definitely don't know the proper magic words to say. Obviously all the words that I am repeatedly and emphatically shouting, as I pound my fist on the table, are not the correct words. It is time to take a long break now and hope for better luck next time.
Thanks again.
Lizardly,
halflizard

I wish to could think of something dumb to say.

To upload a pic, make sure you are logged in, and also make sure you click on the "Reply to Topic" link.

You will then get a new editing window that looks like below. I've circled the camera icon to click when you want to upload a pic. Remember there are restrictions on the picfile, something like <90kB and filename cannot contain punctuation/spaces or certain special characters.

If the file is too large, either use an alternate picture hosting site, or you can crop the stamp picture to show only the portrait.