The phrase "although it was originally" is correct and usable in written English.
You can use it to introduce a contrast or exception regarding something that was initially the case but has since changed.
Example: "Although it was originally intended to be a short film, the project evolved into a full-length feature."
Alternatives: "even though it was initially" or "despite being originally".
Although it was originally identified by its ability to inhibit G1/S progression in human fibroblasts, its role as tumor suppressor is debated.
This camelback pony truss span was moved to its current location in 1938 39, although it was originally built on an unknown location in 1923.
Although it was originally a fictional interpretation of a bank's projects, Hito said that it became a documentary with the development of real world events.
Although it was originally believed that vandals sympathizing with the strikers might have been responsible, an investigation determined the derailment was an accident.
Although it was originally created by Hughes as a tax shelter, the institute is now one of the world's largest and most powerful charities.
Paul Pierce injured his left Achilles tendon in the first quarter, although it was originally reported to be his left foot.
Although it was originally applied to mystical interpretations of the Hebrew scripture, it took on its present meaning from a group of five ministers chosen in 1667 by King Charles II.
Although it was originally concluded that the light momentum increased as it entered the water, thus causing the water to recoil toward the source, recent analyses argue points to the contrary.
Although it was originally developed for a business school environment to promote the benefits of small-group teaching in a large group setting, the method of the team-based learning (TBL) has recently been increasingly used within medical education.
Although it was originally developed as an extension to plan-driven development processes like the Stakeholder Win Win Risk-Driven Spiral Process, it can be adapted for use with any type of development process from Agile to Plan-driven.
Although it was originally believed that enhancers activate only the nearest promoter, recent global analyses enabled by high-throughput technology suggest that the network of enhancer promoter interactions is far more complex.
