Hi Heinzy,
I got Komet struts from Bansbach Easy Lift, Melbourne, Florida. Their web page has a neat "configurer" page where you plug in length, width, throw, N, etc.
I got N2B1-44-350-802-001/1600N...........the 1600N is just about right for a1978 Komet with elevator on the lid. Took them about 4 weeks, they are made in Germany, but you only pay US shipping costs ($275 total).
Changing them was exciting, I hoisted the lid from the shop roof peak, but full open doesn't take the load off the bolts! The hinge bracket bolts must be loosened to allow the top to open another 1/2", then the strut bolts can be removed. At this point you have a couple hundred pound top suspended from a block & tackle hooked around the aft handles. I backed things up with wooden braces, just in case !!
Have Fun,
JJ