All right,
My 318d's timing chain broke, and it has 112,000 miles on it, so I think it would be better to replace the engine instead of just the chain.
Do you have any idea how much work it will be?
The key difference between DOT 4 and DOT 3 is that DOT 4 has a greater boiling point, which is not a problem for clutch hydraulics. Both of these standards are mutually compatible and may be used interchangeably.
The use of any DOT 3 or DOT 4 fluid will suffice for this task. Probably, someone does market a "classic-specific" fluid, but it will be nothing more than a pretentious container; the fluid inside will be identical to what you can purchase at Halfrauds or a neighbourhood auto parts store.