Working with Keycaps Manual Vintage
I've spent years restoring and modifying vintage keyboard setups. The process isn't hard, but it's easy to mess up if you don't understand what you're working with. Here's how I approach it. This is essentially a documentation method for recreating or maintaining classic keycap profiles—the kind you see on machines from the 1970s and 80s. The most common profiles people chase are SA, MBM, and early Cherry OEM variants. Each has different stem dimensions, profile heights, and font styles that affect how the final product feels under your fingers. The manual aspect matters because most modern reproductions cut corners on things like font kerning and profile curvature. If you're serious about accuracy, you need the original CAD drawings or precise measurements. I measured my own SA keycaps with digital calipers—bottom-to-top height, stem length, stem thickness—and then cross-referenced those against published specs from the original Das Keyboard and early SpaceSaver sets. The numbers aren't always consistent across batches. Cherry made variations even within the same production run.
My typical workflow for sourcing or reproducing: Step one is identifying the exact profile and font on your existing keycaps. Look at the legend style—SA uses a clean sans-serif with a specific weight. Cherry OEM has a bolder, more condensed look. MBM caps are taller with a distinctive dome shape. Once I know what I'm chasing, I pull the reference files. These aren't always freely available. Some come from keyboard enthusiast forums, others from paid communities where people have done the measurement work themselves. Step two is checking compatibility with your switch plate and stem type. Most vintage-style keycaps use a standard Cherry MX-compatible stem. But some obscure reproductions use different stem geometries. I once bought a set that claimed to be SA-profile but had a wider stem that wouldn't fit any standard board without filing. Filed it down carefully with a Dremel and a fine bit. Took about twenty minutes per key. Not something I'd recommend for a full set, but it saved me from returning thirty-six keycaps.
Common Pitfalls
Beginners usually assume all vintage-style keycaps are interchangeable. They're not. Profile height varies significantly between SA, MT3, and SKCM reproductions. I've seen people mix SA and MT3 keycaps on the same board and end up with a noticeably uneven typing surface. The height difference is small—maybe two millimeters—but your fingers pick it up immediately. Another issue is font reproduction. Some manufacturers scale the original legends improperly, making the text too light or too thick for the key surface. This becomes obvious when you hold the keyboard up to light and compare it to reference images. If the legends look washed out or too heavy, the reproduction is off. What most guides don't mention: The plastic quality of vintage-style keycaps has improved dramatically in recent years. Early SA reproductions were made from thin ABS that developed shine within months. Newer options use PBT with better texture retention. The trade-off is that PBT is harder on the stem, so you'll see more stem wear over time compared to ABS. I've had PBT SA keycaps that felt great for a year and then the stems started feeling slightly loose after extended use. Nothing catastrophic, but noticeable.
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When It Doesn't Work
Keycaps Manual Vintage as an approach hits a wall with highly customized layouts. If you're building a column-staggered or ortholinear keyboard, most vintage keycap sets don't map cleanly. You'll need to mix profiles or source individual keycaps from different manufacturers. This gets expensive fast. A single SA keycap can cost between three and eight dollars depending on the seller and condition. The manual measurement approach also breaks down if you're dealing with damaged or missing keycaps from a rare set. I once tried to reproduce a single keycap for a 1985IBM Model M that had a broken legend. The original ABS had yellowed and the font was nearly illegible. I ended up scanning the key, tracing the letters, and sending the file to a custom mold maker. That cost over two hundred dollars for a single keycap. Not practical unless the key has historical significance to the build. If you're just looking to upgrade your current keyboard with vintage aesthetics, the simpler path is buying a complete set from a reputable manufacturer. Companies like GMK, Filco, and WOB have released SA-profile keycap sets that are close enough for most users. They won't be museum-quality reproductions, but they're functional and reasonably priced. The gap between a factory reproduction and a custom manual rebuild is visible only if you're comparing them side by side under good lighting.
I keep a reference sheet with my measurements pinned to my workbench. It lists the exact dimensions for the profiles I work with most—SA, Cherry, and MT3. When someone sends me a photo of a keycap they're trying to identify, I can usually narrow it down within five minutes by comparing the profile curve and stem thickness to my notes. That's the practical value of keeping measurements on hand instead of relying on generic spec sheets that often contain errors.
