In case it is of interest, the Movietone Archive is now on Youtube. I didn't do a full SE1 search but searching Elephant and Castle I found a brief item about a partial building collapse, in a film that I would guess is from the 1935 (as it seems to be preceded by a brief snatch of Herman Goering's wedding!):
A web search on the Leete's Paints shop indicated that the building appears to be one of the restored LSBU terrace on London Road, just along from the Duke of Clarence. The building next door to what was Leete's still has the number 128 embossed on it.