Carnaby Street is part of the Soho fashion district in London. Germany's Kaiser Bill (Wilhelm) was Queen Victoria's grandson and "a batman" is a servant. The Carnaby Street Set released "I Was Kaiser Bill's Batman" (Cook - Greenaway) in 1967. The original title was "Too Much Birdseed".

A few weeks later the fictional Whistling Jack Smith cover hit the Billboard top twenty. The name "Whistling Jack Smith" is no more than a "tribute" to "Whispering" Jack Smith. The song performance may have come from producer Noel Walker, Mike Sammes of Mike Sammes Singers fame or John O'Neill an Irish trumpeter who also whistled the theme to "The Good, the Bad and the Ugly". Pictured on the album cover was Coby Wells (Billy Moeller).

After recieving the following message from Michael Thom and adding research I thought I would post it because there seems to be a lot of validity:
"I think you have “I Was Kaiser Bill’s Batman” wrong. Both the WJ Smith and Carnaby Street Set singles were issued in the US in April, 1967. Since composers Cook and Greenaway were behind the “WJ Smith” 45 (a name they made up for their studio aggregation, after which they hired Billy Moeller to “be” WJ Smith for performances), it seems very unlikely the Carnaby Street Set 45 (arranged by Lew Warburton and produced by Mike Smith) came first. I’m fairly sure the Carnaby Street Set 45 was an attempt by Columbia to “cash in” on the song in the US , but Deram got the WJ Smith 45 out here and beat them to the punch.
Interesting that the WJ Smith single charted in the US on 4-29-67, the same week that the Raiders’ “Him or Me” charted. The Raiders 45 differs from the Carnaby Street Set 45 by only two catalogue numbers.
Since the Raiders 45 charted quickly after its release, this suggests the Deram WJ Smith single was likely issued earlier in the month while the CSS 45 was released later in the month."