Nice trademark violation
I can't believe I'm responding to this, but here we go:
• I don't care that you sold the most expensive bag in Ebay history. $350 is beyond overpriced.
• Embroidering the logo is nice, but it's not technically accurate, if you care about such things (which I don't necessarily do). All of the Kirby bags were screen printed, not embroidered.
• No, there are not just 2 embroidery machines per state. I have no idea what you are talking about. I've looked into embroidery. There are over a dozen computer-driven embroidery machines at screen printing shops near me. You pay by the stitch, so a $6 screen print could easily be $10 to over $50 per bag. Embroidery looks very nice and it will almost certainly last longer than a screen print, but it's not an efficient way to recreate graphics. That's why Kirby never made it that way.
• Duvetyne is just one material Kirby used. They also used lots of corduroy, including the original 513 bag I used for the pattern.
• Duvetyne is cheap. You can find 8.4 oz./yd. black duvetyne for as little as $3/yard. One yard can make 2 bags, so your material cost is even lower than mine.
• There are all sorts of Duvetyne available. Did you perform particle tests on various fabric and baseline that against the original Kirby duvetyne (presumably in mint condition)? I doubt it.
• Bill at VacLab has performed particle tests on my bag and it works great: 3x better filtration than an original D50 replacement bag. For 0.3 microns, he found 10k particles vs. 30k.
• The top of the 513 bag does not take "certain material." It uses standard corduroy. On my original 513 bag, it's the exact same corduroy I'm using, right down to the number of wales/inch.
• I find it humorous that you don't want to admit you are using a garter spring. This isn't some sort of proprietary feature. It's just a spring - no big deal if you can figure out where to get more.
• I don't like this idea of hiding info on this forum. It's very tempting to publish my exact materials and where you can buy them, although it will be a lot easier for everyone to just buy a finished bag.
HERE'S YOUR BIGGEST PROBLEM:
• You are violating Kirby's trademark by reproducing it on an item that you sold for a profit! You even posted pics online and admitted your selling price. Not a good idea. You have NOT been granted permission by Kirby. How do I know this? Because I inquired at Kirby and their lawyer called me back to discuss this at length. They even sent me an official email stating their policy. I have been referred to their Engineering Dept. for the possibility that Kirby use my design (and supply chain) to make more bags. However, I'm expecting they won't be interested. Hopefully, I'm wrong about that.
• Their lawyer made it very clear to me that they will only grant permission if they decide to make it an official Kirby product. I can make this bag in a variety of colors to cover every machine from the Tradition back to the first Model C. However, I doubt Kirby will care about this since they only make black shakeout bags now.
• Since Kirby is likely to tell me no, I am considering the idea of asking my art director buddy who was my creative partner at the advertising agency we worked at in SF to design something new for these bags so they aren't just plain corduroy. However, that's probably a subject for another thread.