To identify the early Jacob Baruh Lousadas of Barbados we have collected data as follows:

where we find:

Vere Langford-Oliver:

http://www.ebooksread.com/authors-eng/vere-langford-oliver/the-monumental-inscriptions-in-the-churches-and-churchyards-of-the-island-of-bar-hci/page-20-the-monumental-inscriptions-in-the-churches-and-churchyards-of-the-island-of-bar-hci.shtml

where we find

1470. Da bem aventurada Evirtuoza | Ribcah Mulher de Jacob Baruh |
Louzada que foy Deos servida | Recolher a Milhor Mundo | flor de sua Ydade
em 24 | Menahem Anno 5457 que | Corresponde a primeiro de | Agosto 1697.

Shilstone (ref 61):

where we find

 wife Leah (of Jacob) d 2 Feb 1702 and 2 children of Jacob and Rebecca - Elias d1681 #208 and Isaac d1686 #209.

Wilfred Samuel (ref 5)

 indicates Jacob and Rebecca lost Isaac in 1686 (2 Adar 5446) and Elias in 1691 (21 Shebet 5451); and a Jacob Baruch Lousada witnessed the will of Aaron Navarro on 29 Oct 1685. David's son Jacob returned to Barbados in 1696 with Rebecca (but as can be seen above she soon died). Jacob son of Aaron was born in 1681

Summary and Conclusion:

Of the childrens' graves, there is no difficulty in the case of Isaac's 1686 date as both sources give the same Jewish date 2 Adar 5446 (Shilstone #209 also gives the corresponding burial register entry showing the same date). But in the case of Elias Shilstone #208 gave no corresponding burial register entry, just the date 21 Shebet 5441 which clashes with Wilfred Samuel. As the graves are adjacent and appear in the correct date order compared with surrounding graves, we suggest that Shilstone is correct on this occasion.  

It looks as if Jacob #711 son of David #44 was first married to Rebecca as indicated by Wilfred Samuel (ref 5); then he and Rebecca left Barbados after 1686. On Jacob's return to Barbados in 1696, and after Rebecca died in 1697, he married Rachel (see above) who died in 1710. He then died in Bridgetown in 1711. But Jacob #380 married at about age 21 then lost his wife Leah in Barbados in 1702 before moving to Jamaica where he married Abigail Lamego before dying in 1722 (see above).