I bought a hole punch and former the same size as the outer holes (20mm), plus 50 (smallest quantity I could find!) eyelets in the same colour (brass) as the standard ones. Trimming Shop Group seemed to be a good, reliable supplier. Took 2 minutes to make the new hole in the inner part of the centre reinforcement patch. Simples...
Then I bought an extra pole - same size as the outer ones, plus another couple of genuine Isabella guy lines
I have lots of 20mm eyelets left if anyone wants any - for free! If you buy your own punch/die/former set, don't get the Vaduda kit on Ebay as it's not the right size for the eyelets!!!