This particular UK forger has churned many 1970's signed covers - they have improved their technique recently and unsuspecting bidders have parted with up to £2000/$2500 for this fakery

A genuine Twiggy but a dud Bowie from an American rock memorabilia site which currently  has many Bowie LPs signed by the same person... who is not David Bowie. Beware buying any LP "signed" in this style

Not the worst forgery out there and likely to fool many, this right-hander clearly didn't feel confident (like the Pin Ups next to it) of adding the year. The numbers can help determine if in doubt.

Clever forgery ("For Mike" is very good) copied from several Bowie signed for a BBC producer. It falls over on the "best wishes", autograph and date. Hard to spot unless you seek opinion first though.

Again not a bad attempt and a reasonable effort at the open B style Bowie signed when not in a rush. However, the base of the B curls too far back, the flow at the end of the O never finished like this and the numbers are all way out

This person has churned out 100's of drum heads, A4 sheets  and album covers all signed by Bowie, Ronson, Ian Hunter and Iggy Pop. Sadly they are all pretty good efforts, particularly the Mick Ronson.