Hello everyone,
I posted this the other day in vintage but thought I'd also ask around here.

I picked up an early 90s Alan cyclocross frame, and just finished building it up for my gf to use as a city commuter. The frame seemed to be in great shape when I bought it, but I have now found two stress fractures in the seat post lug. This lug has two sets of "ears," one set on top for the binder bolt and the set below is were the seat stays bolt on. One fracture runs side to side beneath the binder bolt, normal stress from years of compressing the post I assume. But the second fracture really worries me as it runs top to bottom between the lower set of ears where the seat stays attach. Both are pretty small.
I have 0 experience with older lugged aluminum frames, let alone this threaded and bonding method that Alan apparently used. How concerned about these should I be? We don't have deep pockets right now so a full on replacement will probably have to wait a couple months. Does anyone have experience with similar issues and have a sense of how quickly these fractures might develop into a serious safety problem? Am I looking at a gradual decline or will the cluster completely separate while she's riding?

Thanks for reading!