Do you happen to have the raw Flash files or are they only finished swf files? If you have the raw files, you can use Adobe tools to probably be able to convert them.
If you have the rights to the files or can find the original designer/developer, you might be able to get the raw files.
If it is a particularly valuable activity for you, you may be able to find someone to build something similar in HTML for you. ELance (now Upwork) has lots of freelancers that are pretty reasonable. If it is something that can be done in Adobe Captivate I might be able to help. It can publish to both Flash and HTML. Actually, if you love interactive activities, you should look in to getting Adobe Captivate for building them. I am a bit addicted to the software. I love to build interactive activities and lessons with it.