The NJ archives had the ledgers for McCarter, all right. But he recorded nothing about the marriage between Andrew and Eliza. For all of McCarter's marriage slips (there were about 6 of them, total) each had corresponding entries in his ledger, and each was recorded in a timely manner by the Clerk's office. But for Andrew & Eliza, no slip, ledger entry, or Clerk's record.
An unexpected find was that Andrew declared insolvency three times, in 1832, 1835, and 1842 - they had the insolvency petitions, inventories, and discharges. At least once, McCarter - the man who married Andrew & Eliza - was the one sending a sheriff out to arrest Andrew for nonpayment of a debt.
Unfortunately, none of the insolvency documents contained any detail about Andrew's family. No Casterlines or Mainses among the (many) creditors, or anywhere else in the documents. Maybe he didn't borrow from family, or they didn't involve themselves in bailing him out.
Another dead end, but it was worth checking out.