peter,
the 'donation to club funds' would amount to a fee for the club boiler inspector/club for the test,
plus the test would be of no use as if not a member a certificate cant be issued.
the donation route is fraught with problems. it compromises the integrity of the boiler inspector (would you make the donation if the boiler was failed?)
there are certain of the Winsons boilers which are regarded as suspect and will usually receive very close scrutiny on an initial club test. there are quite a few horror stories of defective foundation rings etc.
cheers,
julian