I dont think it's the correct sequential relay either. I remember seeing pics of those installed on the passenger side kick panel of US sold 510's. Same one's?VV
http://www.the510realm.com/viewtopic.php?f=10&t=11912&hilit=sequential&start=15
Put a return spring opposite the way the throttle opens.
Also check #34 on the following link. My carb was binding there and it caused the same issue you have. After a little wd40 , all was well.http://www.racetep.com/weber/32_36DGV.pdf
No datsuns? Yeah right.
I say FL.
There are a bunch of theme parks close to each other in Orlando iirc. Their ocean is probably warmer as well it you plan on taking a dip.