How to get the wyverian blacksmith guy to apear + easy way to get wyvern claws?

[Soulmizute]

i need the lao quest so i can get the lao hammer for los and i need wyvern claws so that i can make clust shots during the fight.

[arkenDuelcalion]

once you've upgraded the workshop to level 3, doing requests given by the workshop staff (forge granny, promising apprentice, forge apprentice, forge greenhorn) will cause the legendary artisan to show up. 2 or 3 requests should be plenty to trigger it, just keep in mind they have to be from workshop NPCs

imo your best bet for quick wyvern claws is through quest rewards for piscine / flying wyverns. cephadrome has the best odds to get them (20% chance for 5 in the rewards), but you can also get some from hunting rathian, khezu, gypceros, plesioth, and their subspecies