Can you specify the exact uses of the server and its requirements? And the components you have and exact specifications, memory etc? What server OS are you using? And an actual budget of £65 will no doubt limit you to auction sites I am afraid. We cant link to such in the forum.
Every so often the HP ProLiant G7 MicroServer which retails around £312 is either on sale or has a £100 cash back.
Failing that, many huge rackmount servers are available cheap on auction sites. Though any regular 775 socket PC with a two core CPU, gigabyte ethernet and Sata HDD is usually fast enough for basic home server tasks that cannot be handled by a simple Nas enclosure. Quite a lot of suitable basic tower desktops available for under £65 on auction sites that are well enough specced, and buying a full tower will get you far more than trying to get a few suitable components ever would for old tech.
My own plan for a server was going to be based on an Asus P5QL-VM EPU with a 2 core E6300 and 4gb of DDR2, it has onboard GPU with HDMI, and can take up to six Sata HDD's. Runs cool n quiet with the stock cooler too. A basic PSU from a Compaq PC runs it OK. Amahi free server OS. (The set up actually resided within a Compaq Presario SR1000 case with a 500gb Sata drive).
I got the Compaq Presario SR1000 case and power supply with the Asus P5QL motherboard, socket 775 E6300 cpu and stock Intel cooler, sata DVD drive, two sata cables, 2gb memory and a 40gb IDE drive for free. No OS.
Usually some papers have people wanting rid of such, pick up only etc, and a lot of such appears on auction sites if you take the time to look.