Alternative Steering Racks

[Chassis 33]

Just looking for some suggestions folks, I've swapped my PAS setup for a reconditioned manual rack a while back as I didn't want the potential for unreliability that the PAS system has (remember my engine fire at Mallory?) However, I've been looking round for spares in case I need to replace it and its a horrid figure, soooo...

Any ideas for a more readily available rack that has similar knuckle to knuckle dimensions to keep the change in steering geometry to a minimum? Modifying mounting brackets etc isn't a problem.

Regards
Iain