Hi Andy,
Just saw this thread & if it’s not too late to post about the helo for your Leander, the only manufacturer that produces a Wasp HAS2 kit is Fujimi, and it’s to 1/48 scale (1/4"=1′), a pretty good kit even for reference. Grumpy is correct as the Airfix model is a Scout, but with some good references from the web a very good Wasp can be produced.
You could use an ealy mark Westland Lynx (Airfix, Fujimi, Matchbox, etc) produced in 1/72, 1/96 (specialist model boat supplier as 1/96 is not a normal scale), 1/100 & 1/144scales (Fujimi also).
Hope this helps
Regards
Neil Lowe