Hi Helen and Kostas.
I had the same problem in january this year. Amel was not able to support with spare parts. Finally I found the parts ( full servicekit with worm-gear and bronce-wheel , bearings and seals) in switzerland. The only problem ist,that the wormgear is for a super maramu 2000, that means the flange fur the motor drive-shaft is different to older super maramus, but for a machine shop it is easy to fix.
Please send me a privat mailing address than i give you more details and Photos.