The top mounts for the Urraco and the Jalpa are no longer available. It would also be the case that no one knows were the originals came from. There were two types. When the top mount bearing starts to fail on the front suspension the car wobbles at high speed. A number of owners have had alternative mounts made. These usually include a rose jointed alluminium plate similar to those used in racing cars.
However my feeling is that you should use something much closer to the original if possible. I have been working along with Robert Box to find an alternative. Attached are some pictures of a mount we have found that we think does the job. it is almost exactly the same dimensions as the original. The base plate is round not traingular but this is easily trimmed down. The biggest issue is the central hole for the shaft of the shock is 14mm but the top mount is 16mm. To correct this difference we have developed a pair of high quality Steel top hats which reduce the size. I have fitted these to my car but am yet to road test them. (waiting for the engine). I will keep everyone posted as to progress but we think they are going to work fine. The most important thing for us is that they are very close to the original design and nothing else on the car needs changing including the spring hangers etc.
Also important is that they are very reasonably priced and will work on front and back of the car.