Interestingly there were eleven vessels named HMS
Endeavour,
1652: 36-gun ship purchased in 1652, sold in 1656.
1694 (Bomb Vessel): 4-gun vessel purchased in 1694, sold in 1696.
1694 (Fire Ship): Purchased in 1694, sold in 1696.
1694 (Hoy): Storeship hoy purchased in 1694, sold in 1705.
1708: Storeship transport launched in 1708, sold in 1713.
1763 (Cutter): Purchased in 1763, sold in 1771.
1763 (Sloop): 14-gun sloop, purchased in 1763, foundered in 1780.
1768 (HM Bark): Converted coal carrier
Earl of Pembroke.
1775: Schooner purchased in 1775, sold in 1782.
1781: 14-gun schooner purchased in 1782 for the American Revolutionary War.
Other regional vessels: Additional replacement brigs or schooners in the West Indies.
I am guessing you are referring to the 1768 conversion that Cook sailed
. If that is the case, one thing that you may find helpful are the many contemporary drawings at the RMG Collections website. If you are building the 1763 version there are several drawings of her at the RMG site as well.
https://www.rmg.co.uk/collections/search/Endeavour plans While these are all in low resolution several of these are also available in HIGH resolution on the Wiki Commons site.
Allan