Mast Rivets for Spinnaker Ring Track

Being "new" to the spinnaker, of course I ripped the track off my mast.  Never one to give up, I need to put in on again.  I see in the "store" Harry has various rivets.  My boat is 3430 (1978) with an 1/8" long by 7/8" wide by 3/16" tall T track.  The rivets need to be countersunk type, except the top and bottom which are round, to keep the ring on the mast.
I am guessing that my existing rivets are 3/16"  solid aluminum.
How long should the rivets be?
I wonder which ones at the store are the right ones?
05123 looks right, but how long does the rivet need to be?
Is it better to hammer them in, or use a pop rivet tool?
Any tips for drilling out the old rivets?
Any help is appreciated for sure.

You put them in with a hammer.
I would ask Harry or Dee exactly which you need.
I did the same thing, and put the track back on, but it's been years.  Mine only tore off the bottom rivets and bent the track.
You use a drill to remove, that is the diameter of rivet or slightly smaller.  If you drill into the center of rivet the rivet will collapse into the hole, and drop into the mast.  I think I also used a larger drill to just cut the head of the rivet, so it could drop through.  Go slowly, to avoid cutting into the track.

Or just remove the track and replace with two rings screwed into the mast like on the current factory masts

On my first, Scot we also tore the pole track off as did my father-in-law on his Scot. 
Best to remove the track and install the 2 seperate ring fittings, which are much stronger and more reliable. 
No reason to have the track, there is no advantage to it and this one significant disadvantage, tearing it off the spar. 
Same deal on the boom with the vang attachment. Replace the old track with a bale fitting which rivets around the side of the spar instead of the bottom of the boom. Never drill holes in the bottom (tension) side of a spar. Just asking for trouble in the form of a bent or broken boom.