There is a very good article about Guyana Rum on the following site
Guyana Rum – Wissenswertes und Tastings
and this is a try of an extract of the Marks
Port Mourant Stil (MPM) or (PM)
Versailles Stil without colouring (MDX)
Versailles Stil with colouring (MDXC)
Enmore Single-Wooden-Pot-Stil (Versailles) with perhaps small colouring directly after distallation (MEC)
Enmore with colouring directly after distallation (REV)
Enmore Single Wooden Versailles Still (VSG)
Uitvlugt Still French Savalle (SVL)
Uitvlugt Port Mourant (PM)
Diamond Liquors Limited (DLL) – Diamond Distillery
Guyana Distillers Limited (GDL) – Uitvlugt Distillery
Demerara Distilleries Ltd (DDL) – Enmore Distillery – eine Tochtergesellschaft von Guyana Distillers Limited
John Dore Double Retort Pot Still (DHE – Highester)
Port Mourant (Berbice) => Double Wood Vat Still with Mark PM
Versailles (Demarara) => Single Wooden Vat Still with Mark VSG and MDX
Uitvlugt (Berbice) => French Savalle with Marques: ICBU and UMS (Uitvlugt), Skeldon (SWR, SM, CG), La Bonne Intention (LBI), Blairmont (< B >), Albion (AN), Port Mourant (PM)
Enmore (Demarara) => EHP (Enmore Henry Porter - Founder), wooden Column Still, MXE (Plantage Mon Repos) + KFM (Plantage Lusignan, Kenneth Francis Mackenzie), ELCR mean a light rum, REV mean havy coloured rum , other Marques are: MEC, MEA, EHP, KFM, REV, MXE, AWM
Skeldon (Berbice) => Mark: SWR (Sir William Ross)
Diamond Distillery (Demarara) => Marques: SVL (Uitvlugt Savalle), SVW + SSN (Continuous – Metal Coffey Still), UN / LSR / GS20 / DLR (Continuous – Metal Multicolumn), DHE (Highester Batch – Metal Double Retort), MPRS (Multi-pressure Rectification Still)
That Boutique-Y Savalle Still ICBU
hope that I have not forgetten too much or any other interesting information
.