Found a value for the C0 correction term that maintains constant total Sr in the system for the 70 degree eq. contact angle (C0 is independent of initial angle conditions). Testing against eq. contact angle to determine a function for C0 in terms of eq. contact angle.
Remaining parameters to test against, initial particle radius, changing the mobility constant value, eq concentrations (requires changing the corresponding energy equations) – all of these terms except the initial radius are in the iteration equations that involve C0 so I may end up having C0 as a function of 5 different variables.