you want to keep it original then I would find correct spindles, they are much more plentiful than the collared ones anyway and not that expensive. There are other things that make the early '61's unique (i.e. thin front axle, rear wheels, no creeper hole, no adjustment hole in dash tower, etc.) but I believe these were phased in, as changes were made, so there are likely multiple combinations of "correct" based on the serial number anyway. Paul Bell would be one to know!
You could use the ones you have until you happen on the bolt topped ones, not a big deal to swap our later.
OH-- and the fenders were not factory, but dealer installed, you should junk them, I would be glad to take them off your hands....
Looking forward to updates,