not really hard to replace .. even if you want one with " everything " and in extramint conditions ... or even if you search the rarest combo ( PN dial with RCO printings ) ..
the only 6263 extremely hard to replace would be the one with Oman crest ( and with a damned consistent case too ...).
6263 it's a beautiful watch indeed but not certainly a rare one due to the very big number produced in 17 years.
just for comparison .. my " estimate " ( LOOLL ) is that the ratio of 16520 R and L ( up to L 350.000 .. so only watches with " special dials " ) vs steel 6263 is in the range of 1: 12.
PP is another stuff .... almost no more around ( and at prices much higher than 2007/8 ).
so your choice has been very smart ...