Good on you, Chris, you found a pair...of wings...
Part #'s in the catalogue are confusing, as Magnum stuff was de-listed
Looks like you have it right, and yes, most parts are common, it's only the rear strut on the SX18 that is specific to the SX, to stop the wings from 'folding forward' in a pitchpole.
You will need SLUGS, STUDS, WASHERS, NYLOCKS to mount the wings to the cross bars. (See Mounting Bar Kit # 6507 1001, or email me how to manufacture your own...cheaper/easier to buy from Hobie). 3 short slugs, one long one, 4 studs, 8 washers, 4 nylocks. As Mike said, Hobie changed from coarse to fine thread on the studs....
You will need clevis pins to secure the bottom of the outboard legs to the TABS.
CLEVIS = # 8020421 with ring ding, need 4.
TAB = #6510 0000, need 4.
Once you're done, if you want to get fancy, you could add the 'Anchor plate' #6819 0001, four of them, plus rivets with caps, although once you mount this, your wings are mounted 'for life.'
email me off line if you need to talk through any issues...
Don't know about tramps....
1989 Hobie SX18 Sail # 1947
'Only two things are infinite, the universe, and human stupidity. But I'm not sure about the former.'