As spotted by Itsyou on LSE ECO board: (CPR p39) 'The Joe Prospect is a stratigraphic channel fill and overbank sand body that trend to the northwest on the northern part of the Orinduik Block (Figure 3-20). This Tertiary feature has positive responses on AVO products and is analogous to the Hammerhead discovery. Inline 2141 (Figure 3-21) shows the feature which will be the target of the second well to be drilled on the Orinduik Block.' Joe is 148.3 MMBOE P50 gross with 43.2% COS.
(CPR p35)
https://i.postimg.cc/5tDHkN4C/ECO-Targets.jpg From this image we can see that Joe overlies the deeper Rappu prospect, which is 535.6 MMBOE with a 25.2% COS. So it looks certain they will drill both Joe and Rappu with the second well, a total of 683.9 MMBOE gross unrisked, 199.0 MMBOE gross risked.
Total gross P50 in the first two wells (Jethro, Joe, Rappu) is 898.4 MMBOE P50 unrisked, 291.7 MMBOE risked with a value net to ECO based on $8/BOE in the success case of £809M unrisked, £263M risked. Using your fully diluted figure of 175M shares that equates to 150p risked, 462p unrisked for the first two drills excluding all other prospectivity on the licence, cash or Namibia.
Note that the first drill was billed as Jethro-Lobe, but I can't see figures for Lobe. The map clearly show Jethro is above another prospect, which take to be Lobe.