Nothing I am aware of as making the frames and sash out of anything other then steel would strong enough

The strength of steel allows for the structural integrity required in a window using very narrow structural members. Using wood components would require additional dimensional sizing of the structural components.

That steel window style shown in the photo is very aesthetically pleasing. If you are concerned about energy efficiency gains with the older window shown, there is one nice alternative to buying new windows. Many traditional homes in colder climates utilized interior hinged, wooden storm windows for these steel casements and transoms. These storm windows were easy to remove and store during warmer weather. The wooden storm windows kept frost away from the interior room side and also added another layer of protection against air infiltration.

Additionally, screens were often of the roll-up or retractible style, with a housing located in the head jamb of the windows. Coincidentally, this is where Pella Roll Screen, or simply Pella, made its way into the window manufacturing business. My recollection is that Pella originally only built screens back in the early 1920's before venturing further into supplying the actual windows.

I am replacing steel windows in my house. Let me tell you on a good day the steel windows may slow down the wind.

At least in my house the steel window is not a structurual unit.

I will be using Marvin casement windows with simulated divided lights.

You have been very helpful, this is just what I needed to know! I appreciate your input.

You might consider aluminum frames. They are very thin compared to other alternatives, so can help retain the look of the original steel frames.