Decode "x-mac-type" and "x-mac-creator"

I’m trying to improve the previews for mail attachments. The content type in a mail describes the attachment. Some old mails have “x-mac-type” and “x-mac-creator” set. But I don’t understand the format of this information. In the horror cabinet of my old mails I found some examples:

[quote]Content-Type: application/octet-stream; name=“MA script 1”
; x-mac-type=“54455854”
; x-mac-creator=“54424236”

Content-Type: application/octet-stream;
x-mac-type=52624246;
x-unix-mode=0644;
x-mac-creator=52427632;
x-mac-hide-extension=yes;
name=“otrTemplate.rbo”

Content-type: application/msword; name=“Membership Renewal 2002?3”;
x-mac-creator=“4D535744”;
x-mac-type=“52544620”

Content-Type: application/octet-stream;
x-mac-type=54455854;
x-unix-mode=0644;
x-mac-creator=522A6368;
name=“XERDBeta1Notes”[/quote]

One attachment has a file ending (rbo) and one a mime type (msword). I know that the other attachments are text files. But how do I decode the values of “x-mac-type” and “x-mac-creator”? It’s not base64, not hex and not ascii. What else could it be?

I am pretty certain they are HEX.

54455854 = "TEXT" 54424236 = "TBB6"

Obviously, my brain is also going somewhere. Thanks!