No window dealers please. Please answer from experience only. I need to replace the windows, because they don't raise and they have storm windows on the outside, I can't get into them to wash them. They also steam up a lot between the outer window and the storm window.
Pella is a good brand, but there are a lot of other choices. Hurd, Anderson, Eagle and three other national brands, but there may be local brands available to you at a somewhat lower cost.
Installation is probably more important than choosing an exceptional window over a good window. Poor installation will negate the extra money you pay for an exceptional window. Ask your neighbors what they use. Get references from your installer and call them. Check the Better Business Bureau.
Anderson makes replacement windows. Those replacements by Anderson are WOOD windows not that junk plastic stuff the locals sell. I dont think Pella makes replacement windows to size. Only Anderson.
You 1940's house will look awful with those junk plastic windows the local window companies sell. Get those Anderson replacements, they cost about 10% more, they come out and measure them and make them to size in their factory in Minnesota. Nice wood windows to match your house's original construction.