Hi Sue -
For sure they were brothers.
1861:
RG9 P.1373 Fol 27 Pg 8
Fore Street, Colyton
James Sellers head M 47 Druggist B. Lyme Regis, Dorset
Sarah Sellers wife M 42 B. Colyton, Devon
William Goodage son-in-law 16 B. Exeter, Devon
Thomas Goodage ~ ~ ~ 12 B. Exeter, Devon
Samuel M Sellers Son 6 B. Colyton, Devon
Walter Sellers Son 5 B. Colyton, Devon
Amy Sellers Dau 2. B Colyton
1871
Walter is a Bakers errand boy, living in Kenton.
James Sellers Head M Druggist B. Lyme Regis
John P Sellers Son 9 B. Colyton
Can't see Sarah or the others - will keep looking.
But this is certainly the same father, although the index says Tellers, the image is Sellers!