Before asking for help, I would try to gather as much information as possible about the format. Wikipedia is a great resource for this, as is the physical formats section of the Archive Team File Formats wiki. For reference this is a list of floppy disk formats the Archive Team has documented.
Once you have enough information, the following are some good resources to ask for help. These aren't service providers, but they might be able to connect you to someone that can help.
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This site
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BitCurator
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Computer History Museum
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Hobbyist Communities
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Twitter
Finally, if you couldn't find a lot of information, but you do find help, contribute that information back to the community by adding information to the Format Wiki, answering your question here if you asked one, etc.