Edit 3: V2.1 re-uploaded the files but exported again from SolidWorks with better detail.
Edit 2: V2 uploaded with corrected bolt pattern. The data-tag can be placed anywhere you want. In real life there's sometimes little rhyme to reason where they are, and are sometimes missing or buried under insulation.

I've had this concept floating around for a year or so for a Heat Exchanger business card holder, I'm an API 510/570 Inspector so I get real up close n personal with these in oil refineries and chemical facilities. With the quarantine still mostly in tact and my industry still mostly not doing much I had the time.

Print with supports as needed, the body needs to have slightly more infill to help with the weight balancing and distribution as in the field these things are bolted into the ground or concrete pads. But for holding cards it should be fine. I'll be printing this with 0.2mm layers with a 0.4mm nozzle since my larger corexy is still being re-built. But feel free to print as you see fit. You only need to print one of each, due to the way exporting assemblies to .stl works in solidworks there's now enough of everything

The bolt holes have a size of r-1.1mm so you can use M2s or the ever elusive M1s or you can glue it all together. But if you glue it together you will ruin the surprise. If you fear nothing then feel free to soften and shape some filament to go in the u-bend tube sheet section of the exchanger (the end cap without the nozzles) for extra authenticity. If you do have things to fear I can upload a body without the tubesheet no sweat. Also if there's any interest I'll split the body with the legs and make those separate.