So...........those are just promo illustrations BSA threw together, right? Would be very curious if they really shipped a wasp with two 689s on it.
Yes and no.
Small Heath mocked up this years bikes to make next years bikes and in most cases the catalogues from the UK were painted images and in many cases, nothing like what the factory made months latter.
Next seasons catalogues had to get to the dealers by the end of this seasons sales to generate orders for next seasons bikes thus they depicted bikes that had not been made yet.
Second edition catalogues and in particular those printed in the USA were generally photos of actual bikes but again some license was taken with the fitting of non standard parts or changing the colours.
The first editions of the 1962 catalogues show all pre unit bikes
The second edition, printed 2 months latter shows the A 50 / A 65 , ( suggesting the release was pushed forward )
UK versions of catalogues would oft show one colour while the USA version shows the alternative colour.
The B25 / B40 range were usually opposite colours in the UK & USA catalogues.
Note closely the line at the bottom of the catalogue, regarding
Minor variations to East & West versions.
In general the USA got all the new stuff first and the UK versions got the older parts till the stock ran out then they fitted current model parts.
Also the higher profit 650 cc variant will always get the new higher performance parts while the less profitable 500 cc variant got the old bits that used to be fitted to the 650, till they ran out.
This is one of the massive problems when trying to do a concorse judgment on a BSA
FWIW dealers would also fit whatever parts the purchaser wanted ( for a price ) so very likely that the blue parts were substituted at dealer level.
Both red & blue tanks are listed in the BSA accessory catalogue and if it was a factory authorised part, no problems with the dealer changing them pre sale.
The only definate way to check is to get a certificate from the BSAOC UK from the despatch records which generally ( but not aways ) list non standard parts factory fitted and colours.
AS for paint or gel coat, the fiberglass B 25 tanks & side covers were blue fiberglass, not overpainted red and they are also listed as "Saphire Blue" so making a very dangerous assumption ( for what BSA did ) one might be led to think that the Wasp glasswear was blue all the way through.