Distributed storage systems need to guarantee reliable access to stored data. Resilience to node failures can be increased by using erasure encoding. A variety of erasure codes are discussed in literature and implemented in practice. This multiplicity of codes puts a heavy burden on existing systems. In scenarios such as multi-cloud file delivery or migration of data to a new erasure code, the ability to combine data from diverse erasure codes of multiple cloud systems is essential. The methods presented in this paper enable combining symbols of different erasure codes regardless of their underlying generator matrix, finite field size, and source block size. Mathematical approaches are discussed using Reed-Solomon and RLNC codes as example but without loss of generality. The presented approaches enable multi-cloud file delivery across diverse coding algorithms and permits graceful migration of a legacy erasure coding without the need of re-ingestion of existing data.