If a baby who is a Bechor had his Bris delayed beyond the 31st day - should the Pidyon HaBen be pushed off until the Bris is ready to be done? On one side you do not want to delay a Mitzva in its proper time, on the other hand Bris Milah is the foundation of the Jewish people and without this covenant between Hashem and Klal Yisroel there would be no Mitzva of Pidyon Haben. (sources please)
Excellent treatment of the clal 'ain maavirin al hamitzvot' http://www.dailyhalacha.com/Display.asp?ClipDate=7/16/2006 You perform the Pidyon at its proper time. A delayed Brit may follow.
Citing The Chida (Rabbi Chayim Yosef David Azulai, Israel, 1724-1806), in his work of responsa Chayim Sha'al (1:31), writes that even if an infant is sick and unable to undergo (brit Milah) circumcision, the Pidyon must not be delayed; it should be performed immediately once the obligation takes effect on the thirty-first day, even if it is before the Brit Milah.
Firstly you claim that "Bris Milah is the foundation of the Jewish people and without this covenant between Hashem and Klal Yisroel there would be no Mitzva of Pidyon Haben" without providing a source.
Secondly, the Mitzva of Pidyon HaBen is an obligation on the father - who did have a Brit. The firstborn is merely the cause of the Mitzva (and does not even have to be present). Compare it to redeeming a firstborn donkey which is also not part of the Jewish people.
So the usual rules apply: When it's time for a Mitzva then you do it ASAP.
For actual sources you can look up these:
- ספר נשמת אברהם שח, ב (by the חיד"א)
- שו"ת חיים שאל א, לא