Allwood Sails source Riley marine fittings from the manufacturer.  Riley marine fittings are made in Australia.

Allwood Sails in Sydney sells Riley Red Roller 21mm x 8mm blocks:

RM304      inlet – outlet block for $25
RM801      single block for $17.65
RM801B    single block with becket for $21.65
RM802      double block for $41.75
RM802B   double block with becket for $16.15
RM803      triple block for $62.60
RM803B   triple block with becket for $67
RM804      angular mounted deck block for $21
RM805      swivel block for $28.20
RM805B   swivel block with becket for $32.60
RM807      stand up block for $23.85
RM809      turning block for $21.70

Click on the image below to go to the Riley catelogue: