Rear spar carry thru repair

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I have a C337E which had a repair to the rear spar carry thru 1512106-1 done in 1975. The log book entry says the repair was carried out as per the Cessna instruction. However there is no mention of a repair scheme number. The repair used part no. 1512196-30p. The repair is a doubler over the left hand end of the rear spar carry thru assembly. The bottom of the carry thru had a wrinkle damage cut out leaving about a 1" gap under the leftmost lightening hole. The doubler was placed over this damage and bolted & riveted to the spar carry thru assembly.
Does any one know if this is a legitimate Cessna or other part number and legitimate Cessna repair.

The aircraft has just completed the Cessna SID inspections and the mechanic is concerned that the repair is not compliant as it was not correctly referenced in the log books.
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