Hi. Sorry if I'm responding a bit late. I have two similar teapots. 
The first I bought cheap many years ago thinking it was 18th century 
Jackfield ware--nope, just the ongoing use  of similar clays and 
glazes a long time after the "handy dandy revised sherd 
identification key table" stops. The second I bought not many years 
later because it has the impressed base mark "SADLER MADE IN ENGLAND" 
done in a circle. The Sadler one is definitely the favorite "Brown 
Betty" that was first made in Burslem in 1881 and is still in 
production, I think. Numerous knockoffs and copies, but the dense red 
paste and dark brown glaze with just a bit of sheen are diagnostic. 
"Victorian sensibilities" overcome 2500 years of Asian 
teapots?  Enquiring minds want to know. We still use both of course.

.At 07:06 PM 2/21/2011, you wrote:
>Feb. 21, 2011
>
>Hello all,
>
>I have, from a Japanese boarding house in San Diego, 1 large solid 
>dark blackish brown teapot.  It has no variation in glaze color it 
>is uniformly solid very dark brown.
>
>I just had a local collector of Japanese ceramics here and he flatly 
>said it was not Japanese.  (I agree.)  To me it looks like English 
>or American made "Rockingham".
>
>But the paste is red.
>
>Jane Perkins Claney's Rockingham Ware in American Culture, 1830-1930 
>(2004) defines Rockingham as on white or yellow paste.
>
>Mary Brewer's book Collector's Guide to Rockingham (1996) , page 9, 
>says Rockingham glaze was put over an earlier yellow glaze "that 
>went over a redware paste" (my emphasis).  This is not the case 
>here; it is glazed directly over the red paste.
>
>It does not look like the photos of redware (with Albany slip) I 
>have seen.  (Don't find redware here either in local assemblages.)
>
>Anyone else ever hear of solid brown Rockingham like surface 
>decoration on red paste?
>
>Or do you call such stuff by another name?
>
>Thanks for your attention and help,
>
>S. Walter