That is a very early block #. I believe the block #'s started with "00001", or close.
For car VIN info visit my website at:
Main page:http://www.geocities.com/provamo72/
VIN page:
http://www.geocities.com/provamo72/VINDecoder.html Car VIN started with 1001. So block and car #'s won't be the same, but the block number was stamped in two places, one on the footbox plate next to the brake booster.(Motour # ?) The other location was on a plate mounted on the left side (as seen from back of car) of the engine bay near the gas filler/deck lid shock area. USA cars also had a timing/smog plate here too.
See:http://www.geocities.com/provamo72/IDBadges_1.html
for examples of these and other plates or badges...
BTW: I don't consider 2 bolt blocks to be any weaker than 4 bolt blocks.
Chuck