Hi Dan,
The Cdn govt site only lists Seth as a postmaster, so one (like me) would think that the post office was in Seth's house, but then I don't know how Seth and Edward are related. Then again, maybe the heritage book isn't correct. People wrote from their memories.

the only other ones I see mentioned in the 1911 census are:
Morley Dodman, b. June 1895 who is working as a farmhand on the John Bartgen farm
1911 / Saskatchewan / Moosejaw / 52 Townships 24 / page

And
21 21 Dodman M Head M
22 21 Dodman Elizabeth F Wife M Dec 1858 53
23 21 Couch Henry M Uncle M Dec 1847 63
1911 / Saskatchewan / Moosejaw / 51 Townships 23 / page 2

Is this your Couch family in Manitoba in 1906?
26 84 Couch Joel B. Head M M 58
27 84 Couch Addie L. Wife F M 47
28 84 Couch A?mond Son M S 24
29 84 Couch Harry W. Son M S 19
30 84 Couch Ivan C. Son M S 17
31 84 Couch Merton B. Son M S 14
32 84 Couch Gladys Daughter F S 11
33 84 Couch Eva Daughter F S 8
1906 Census Page Data
District: MB Portage la Prairie District (#6)

There are quite a string of Couch's to be found on the Manitoba Vital Stats website, altho' I don't know if any pertain to you. Likewise a few Dodman's. You might check them out.

I'm afraid I'm striking out here.
Sorry,
Bette

Subdistrict: 19 A (Town of Portage la Prairie) Page 12
Details: Schedule 1 Microfilm T-183551906 Census Page Data