Vintage Shimano 600 or Beefy Deore LX?

Hello everyone. I recently converted my Voodoo Wazoo cyclocross frame for road riding. I replaced the front crankset with shimano dura-ace, installed a new chain (HG-70), and a mounted a road break in front. I was planning on installing a vintage shimano 600 rear deraileur, but now with it on, I am questioning whether it is a wise choice. This is an actual vintage 60s derailleur, not like one from the early 90s on ebay listed under "vintage." Bizarre. I have not yet hooked up a cable. There are 3 things that make me suspicious. The first- after insalling the bolt to the frame, the derailleur's mount is not completely flush with the derailleur hanger. It stops right around the C-clip, not allowing the catch to be right against the hanger (compatibility issue?). However, by adjusting the H screw, I am able to bring the guide wheel into proper allignment. 2- There is no adjustable "B" screw to adjust the catch.....which brings me to 3- I am unsure if the spring inside the mounting bolt housing is sufficient enough to operate fully. It seems a bit weak. With the derailleur on the smallest cog, there is a distance of 3 links between the cog and guide wheel. This seems like too much compared to past experience.
Is everything with the 600 normal/okay? Should I just go with the LX which was on it before? I was wanting the 600 since it's so stylish and actually for road instead of MTB. Let me know, FasterthanU