The pilot reported that the landing gear indication lights showed only two green when the gear was selected down in the circuit at Palmers Island. After checking that the third light bulb was serviceable, he slowed the aircraft on base, and the gear warning horn sounded. The pilot was able to contact the owner of the strip on a mobile phone, and explain the situation. He then carried out two missed approaches, and the strip owner advised that the right gear was not locked down and was hanging at a 45 degree angle. The pilot then tried the emergency method to extend the gear, and yawing and positive g manoeuvres, without success. He then decided to return for a landing at Coolangatta where emergency services were available. On arrival at Coolangatta several more unssucessful attempts were made to lower the gear by normal and emergency methods. The aircraft was finally landed on runway 14 on the left main and nose gear, with emergency services in attendance. Post flight examination of the gear actuating ram revealed that paint on the ram had caused a seal to roll up and effectively jammed the actuator.