Jabberwok
It might not be the info you are after but you might be interested in the prices DH asked in 1929 for float equipped Gipsy Moths the following extracted from price list No 5 dated July 16th 1929
Wooden fuselage seaplane £950. 0. 0d (Ex seaplane station ready for flight)
£910. 0. 0d (dismantled ready for packing)
Metal fuselage seaplane £995. 0. 0d (Ex seaplane station ready for flight)
£960. 0. 0d (dismantled ready for packing.)
Complete float undercarriage £310. 0. 0d
Attachement fittings to enable fitment of float undercarriage £3. 18. 6d
Beaching trolley £17. 12. 0d
Hand pump for draining water from inside Floats £1. 17. 6d
Set of lifting cables wth attachment fittings on centre section of fuselage £4. 9. 6d
Wunper