If you sold it would you replace it with something similar? In other words, it might be more cost effective to have it repaired, especially as values seem to be rising, than to buy a replacement.
It is quite an alarming list for a low mileage car, but, as has been mentioned already, the most serious (and expensive) issues are the corrosion and the engine oil leak. From the cars currently being advertised I would guess that the value, once repaired, would be over £5,000, assuming the bodywork and interior need no work.
If it's a "hobby car" and you don't intend to replace it then perhaps just cut your losses and sell it for spares or repair. Apparently the engines are becoming popular for those who want to convert to V8 power, presumably having supplanted the trusty Rover/Buick V8.