Reflectix insulation behind finned tubes
My house, brick, 1920s, no wall insulation, has a 1980s hydronic boiler with finned tube radiators below the windows (see picture). The finned tube enclosures have steel metal sides and a steel vented front. I have a few questions:
1. Were finned tubed radiators in use back in the 1920s when my house was built or is it more likely that the original radiators were replaced at some point?
2. I am thinking of taping Reflectix insulation to the steel enclosure behind the finned tubes to reduce conductive heat loss through the walls.
Is this time and money well spent, or is there a better approach? Or should I leave well-enough alone? Insulating the walls is not in my budget for at least several years.
3. On some of the finned tubes, there is very little clearance between the metal enclosure behind it and the fins. If I use the Reflectix material, is there any potential harm if there is any contact between those rear fins and the Reflectix?