This is a very simple pattern, with the front and back of the rabbit, in this case the small version, only 12 inches tall, cut the same. Note that this is Peter's Winter suit. Perhaps for summer he didn't wear the jacket.
This pattern was well-loved. There are several cellophane tape repairs to the rabbit, and the envelope has been pinned closed repeatedly. It's interesting to speculate how many children were given this bunny, nattily turned out in his overalls and jacket.
At first I thought the pocket piece was missing (in people-sized garment patterns the pocket pieces often go missing.) But when I checked the envelope again, I found the maker had carefully pinned the tiny pocket piece to a scrap of blue fabric, possibly left over from the bunny's jacket.
The maker worked out the embroidery for the face on a discarded mimeograph sheet (remember mimeographs?) for some sort of event.