I got one: i can overclock it easily using ATI Tray Tools, heres the system info i get from the card:
______________________________
General
Display adapter Radeon X800 VE (4A54)
Core Name R420
SubVendor ATI (1002)
SubDevice 4422
BUS 1
Device 0
Function 0
Base Address 0 E0000008
Base Address 1 0000C001
Base Address 2 FD600000
Base Address 3 00000000
Catalyst Registry Path
System\CurrentControlSet\Control\Video\{42779E2D-9667-48BE-B9E5-46D694D1C5A7}\0000
______________________________
Clock Information
BIOS VPU 425,00
Current VPU 522,00
BIOS MEM 400,00
Current MEM 549,00
______________________________
Radeon PCI configuration space
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00 02 10 54 4A 07 01 B0 02 00 00 00 03 40 FF 80 00
10 08 00 00 E0 01 C0 00 00 00 00 60 FD 00 00 00 00
20 00 00 00 00 00 00 00 00 00 00 00 00 02 10 22 44
30 00 00 50 FD 58 00 00 00 00 00 00 00 10 01 08 00
40 00 00 00 00 00 00 00 00 00 00 00 00 02 10 22 44
50 01 00 02 06 00 00 00 00 02 50 30 00 1B 02 00 FF
60 12 03 00 1F 00 00 00 00 00 00 00 00 00 00 00 00
70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
80 05 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
______________________________
Hardware Information
Installed memory 256 Mb
Memory Type GDDR3
Memory Width 256 bit
Active Rendering Pipelines 4
______________________________
ASIC details
Family 56
Emulated Revision 2
Gfx Engine ID 3
______________________________
Radeon Registers
RADEON_BIOS_0_SCRATCH 00000002
RADEON_BIOS_1_SCRATCH 0100C000
RADEON_X_MPLL_REF_FB_DIV 003A3D03
RADEON_XCLK_CNTL 00007FFA
RADEON_MCLK_CNTL 00031212
RADEON_XDLL_CNTL 0400A430
RADEON_XPLL_CNTL 48001200
GB_TILE_CONFIG 00010011
MC_TIMING_CNTL 69668234
MC_SDRAM_MODE_REG 10430000
MC_REFRESH_CNTL 00007030
______________________________
Video BIOS Information
Version 009.004.002.001
Part Number 113-A38308-102
Date 2005/04/27 11:43
______________________________
Controller Configurations
Controller 0
Active Connections:
-Monitor (CRT1) and TV at 1152x864
Controller 1
Active Connections:
No Active Connections
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Displays supported by adapter
0 (1) Monitor (CRT1)
1 (2) Second Monitor (CRT2)
2 (4) Component Video Output
3 (8) TV
4 (16) Digital Flat Panel
I hope that helps

As you see i overclocked it at 522/549. But max and still more or less stable is 549/585. not bad eh?