Thank you for your excellent questions.
Yes, Science ASSIST would definitely encourage you to recycle any science equipment that can be used. Many schools have limited budgets for science equipment purchases and would welcome useful donations. We note that one expression of interest has already been posted to your question on our website.
A good first step would be to make a list of the equipment that you would like to dispose of. This could include the name of the item, the brand/model number, and perhaps a photo and/or a brief statement as to its condition. This list would be useful for any schools that show interest in receiving items.
Science ASSIST does not have the capacity to undertake the distribution of second-hand science equipment. However, we can direct you to your local science education associations within the ASTA and SETA federations, that is, your local state Science Teachers Association, and your local School Science Technician Association. Many of these networks quite often advertise second-hand resources. Disposal to another school is probably most easily arranged with schools in your own state, and/or which are geographically close.
Regarding your second question about mercury sphygmomanometers, our advice would be to arrange for them to be collected for disposal by a licensed chemical waste disposal company. Not only are they not appropriate for school use, but most medical practice now also use instruments that work on electronic pressure sensors rather than mercury columns.
Although the mercury may be fully enclosed within the sphygmomanometers, the toxicity of mercury means there is no way to dispose of it, other than by a licensed chemical waste disposal company.
Items such as mercury sphygmomanometers (as well as mercury thermometers), which are no longer required and are not broken, should be collected and securely stored in a container to protect them from damage until collection by a licenced waste disposal contractor.
Links to Science Teacher Associations: http://asta.edu.au/
Links to Technician Associations: http://moodle.asta.edu.au/course/view.php?id=32
Links to licensed chemical waste disposal companies School science suppliers
Related question: Mercury Thermometer.