In our experience a copper film on iron is very fragile, but nickel is robust on iron and copper.

For nickel coatings we use

NiSO_4*-6H_2O (0.95 mol/L)

NiCl_2*6H_2O (0.19 mol/L)

H_3BO_3 (0.65 mol/L)

with 100 mA/cm^2 (Y. Matsubara und H. Hamada, J. of ASTM Int. 3, 1-13, (2006).)

And for copper coatings we use

200mL H2O

6mL H2SO4

13mL Ethanol

25g CuSO4*5H2O

With 0.1 mA/cm^2

Thanks Martin. Could you also comment if the following order of deposition will work if we disregard iron? i.e. a film of Cu, then Ni, and finally Zn?

I have never used Zn, but Ni and Cu can be coated on each other with good adhesion.

As galvanic chemist I can say by experience yes.

Cu on gold is possible (important a good preparation of gold surface)

Nickel on copper is possible (i do, important nickel agitation and temperature 50°C)

Iron on nickel, possible but is important that nickel is not passivated or you may face lack of adhesion. To avoid this is important Nickel never become dry, so after nickel plating you have to rinse and plate iron in few minutes; (you may leave nickel plated substrate in the rinse for minutes before iron plating). Iron plating has to be done with hot solutions (60-70°C) to have a good layer

Zinc on iron is possible (is available in commerce iron protected by zinc).

Feel free to connect me for details on  the solutions and the parameters. 

My best

Cu, Ni, Fe and Zn, respectively on a gold layer. Is such sequential deposition possible galvanostatically?