There's only only one John Cross baptism in Tilbrook, on 31 Oct 1773, the son of John and Lettice/Letitia, who were the only Cross couple who baptised children in Tilbrook.
A John Cross was buried in Tilbrook on 9 Nov 1773, and as John and Letitia baptised children until 1789 I assume this must have been the infant John. But why would John and Letitia not have baptised a John born 1777? Letitia was buried in Tilbrook on 2 May 1803
Have you checked the parish register to see if there any gaps or possible misenumerations?
David