MTech II suspension advice please

[666JSB]

I want to use my 90/04 build 325is MTech as a daily driver, it's been summer driven only for the five years I have owned it and I want to have fun all year round! I want to revert back to the factory suspension.
It was imported to Canada from Japan just before I got it and it had been lowered, previous owner had left the old springs in a box in the boot. Box was marked COBRA 001446 - BMW E30 6 Cylinder full option. I checked their website and for this product it states that it would be 40 front and 40 rear, does this mean it's lowered by 40mm? Other than this I have no idea what's been changed.
The original (I guess) front springs are @310mm long and the rears appear brand new, they are @190mm long.
My question is: Would the lowering have included new or different shocks? Are these spring lengths standard?
Any advice would be appreciated, I want to know before I start taking the suspension apart what I'm getting into.

I have attached a pic so you can see how much it's been lowered roughly.
Thanks for your help.

[666JSB]

Strange, on closer inspection it looks as though the original springs have been left on the back, they are still fairly clean and black in colour - the 190mm long rears are greyish/white, appear brand new and match the colour of the front springs. Maybe the previous owner decided the fronts only should be changed.

I want to get away from the very solid, harsh ride and very low ground clearance so I need any advice as requested - would it have been a spring change or shocks as well possibly?

BTW, the car has only done 64,600km, @ 39k miles so it's all looking as new original paint and no rust or oxidisation underneath so I can see what's original and what's not.

Any ideas? Am I correct in my estimation the fronts only have been changed and it would be springs only?

I hope so - my next question will be how big a job is it ro re' & re' the old front springs?