Brass badges
I have had 4 800s, only 1 had an aluminium badge. The others have brass badges. 1 has the paint almost completely polished off it.
As far as I know, the brass triangular badges were used on the top of the range machines up to 1932 ie. Model 700, 725, 750 (orange with black edging). In 1934 both the 800 and 450 had brass triangular badges. The 800 was black with gold edging; the 450 was orange with black edging - the last orange badged machine and also the only one incorporating the royal crest. For 1936 both the 825 and 475 had brass badges but in a rectangular shape - but chromed so they are silver. Most of these have suffered from overpolishing through the years and so the brass shows through.
The cheaper priced machines such as the 425 and 575 started life with the black aluminium badges. After the war Hoover did a generous part exchange programme and thousands of pre-war machines were refurbished and resold by them at Perivale. These machines were re-polished which meant that the original badges had to be removed for the repolishing process and presumably chucked. The freshly repolished Hoovers were then refitted with the black aluminium badges - the standard badge which Hoover had for reconditioned machines. It stands to reason that a lot of these reconditioned machines survived - they were given a new lease of life by Hoover!
I have had a number of the rebadged machines come through my hands - notably an 825 with a black triangular badge! I removed the badge and underneath it were the 2 original holes for the rectangular badge!