It is punIyAd ari-nalina-gadA-ZaGkha-pANir mukundaH
AnandI
ri-nalina-gadA-ZaGkha-pANir mukundaH =
AnandI = "the blissful
mukundaH = Mukunda,
ari-nalina-gadA-ZaGkha-pANir = Who holds a disc. a lotus, a mace, and a conch shell in his hands,."
punIyAd naH = let purify us.
I have just corrected your interpretation close to the text. You missed some point and I made it out. punIyAd is benedictory mood, पूञ् पवने to purify.
and ari is disc, or cakra. having अर-s. the word is अरिन् in the neuter.
GarPur, 1, 45, 5.1
namo gadāriśaṅkhābjayukta ca /
GarPur, 1, 45, 8.1
sāriśaṅkhagadābjāya vai namaḥ /
GarPur, 1, 45, 9.1
suśaṅkhasugadābjāridhṛte /
GarPur, 1, 45, 9.2
namo gadāśaṅkhābjārīvidhāriṇe //
GarPur, 1, 45, 10.2
namo gadāśaṅkhāripadmine //
GarPur, 1, 45, 11.1
padmagadāśaṅkhāridhāriṇe /
GarPur, 1, 45, 11.2
padmāriśaṅkhagadine namo ' //
GarPur, 1, 45, 13.2
sagadābjāriśaṅkhāya namaḥ //
All in the same expression for Vishnu. It is not uncommon.
--