Hi @mattdvdsoncox,
Welcome to the community. What you described is definitely possible with Mapillary. It’s really easy for anyone to contribute geotagged photos using our apps or with action cameras. If you wanted to keep track of the project, you might want to contribute under one account so you can easily view all contributions.
At the end of the project Mapillary JS and or our API will be really useful to help you to highlight the derelict sites.
Feel free to reach out if you have any other questions.