My coil is acting up, are there any recommendations , or just replace with stock?

 

When you state "acting up", what do you mean, exactly?
Have you tested the coil for output?
Have you tested the internal resistance to determine if it's bad?

 

Faulty coils are unpredictable, they can bench test just fine, but as soon as they heat up under real world conditions, the internal resistances change and cause misfiring.
Coils are cheap, the only way to be sure if the coil is faulty is to substitute with a known working coil.
What happens is that over many years of heating and cooling (expansion and contraction) of the copper windings, the varnish that insulates the copper wire breaks down, this can cause internal shorting and out right failure. The shorts cause weak/intermittent spark.
Generally the shorts/failures usually occur in the secondary winding _ the secondary winding have thousands of turns of very fine copper wire and are more susceptible to failure.

Any 12 volt coil will work, but make sure to get the correct one _ with an external resistor or none.
The coil needing an external resistor will have around 1.5 ohms across the primary windings and the coil that doesn't need an external resistor will have 3 or more ohms across the primary windings.
That is the resistance across the negative and positive terminals of the coil.
With out checking, your Daimler uses a 3 ohm coil.

Also, the coil on the Daimler is probably mounted side ways, so an oil filled coil can leak over time.
A coil that is epoxy filled is recommended, but make sure that the coil is the problem before going out and spending money on an epoxy filled coil.

 

Mechanics tell me the spark is orange, not blue, so replace. Other than that it
has not been tested. (it's not their money, so it's simple for them, replace)