What you're looking for are issues 22-26 of BAM! Or Bulldog Adventure Magazine to give it its full title. I have issues 23 & 25 so I'm looking for issues 22, 24 & 26. Images are taken from this handy guide to collecting The Rainbow Orchid that Garen has uploaded to YouTube for posterity.
You get 6 pages of B&W art in issues 22-25 and then 8 pages in issue 26 - a total of 32 pages. All of this material was then collected in The Rainbow Orchid part 1 (from King Rat Press) plus 2 additional pages and 6 pages of covers/additional material - giving a total of 40 pages for the 'part one' edition (published in 2003)
BAM! issue #22
BAM! issue #23, Spring 2003, £2
BAM! issue #24, Summer 2003, £2.50
Garen has a very detailed look at the publication history of The Rainbow Orchid on his website here
other contributors to this (40 page, B&W art, A4 sized) issue include PJ Holden, Ed Traquino, Paul Harrison, Kieran Macdonald and Russell Ferguson
BAM! issue #25, Autumn 2003, £2.50
other contributors to this (40 page, B&W art, A4 sized) issue include Jason Cobley, Ed Traquino, Neill Cameron, Nigel Lowrey & more
BAM! issue #26
The material was then collated (in October 2003) in this 40 page reprint collection. Precise number of copies printed is unknown but is at least 100 as Garen mentions he sold 100 copies at the Winter 2003 comics festival in London. I went to that convention but wasn't into small press comics at the time so it's taken me 20+ years to get hold of a copy - more fool me!