just from pictures I thought he was entombed in the same manor as JPII
it wont let me post the picture of his tomb but its at the bottom of this page
http://en.wikipedia.org/wiki/Pope_John_Paul_I
if he was entombed in a different manner it was probably because it was his wishes to do so. he like all other humans have the right to decide how he wants to be buried or what have you.