It sounds like most of your problems are Mechanical, if the 10T is still in fairly good shape, I would try and keep it, it was not a bad control, If it has DC servo's, remove them and clean them out and replace brushes or send them to a local Motor shop for cleaning.
For the limits, I would replace them with Honeywell hermetically sealed type.
The oil system would need a complete clean out as lube oil congeals when stood for a long time, replace the metering devices that are at the end of the lube points. The Original are probabally the same as Bijur style.
The Electrical problems with the spindle drive may be cured if you can fit a 3rd party drive, if it is analogue control, Is it DC or AC spindle?
If it has proximity switches (Unusual)! I would replace with the above type.
Al..
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.