Loctite vacuum impregnation. As of 2013, cost for sealing a V8 cylinder head is about $200.00. Not a bad idea considering the porosity of the Lamborghini cast aluminum head.
Located in the UK, they can re-manufacture impossible-to-find bearings for our vintage cars. This includes the RIV bearings used in the chain idlers. Point of contact is Mr. Alan Rolnick.
They are located in Italy north of the town of Trento. Mainly a Ferrari source but they have an extensive inventory of hard to find parts for early Lamborghinis. Check their website.