I built a clone of the prescaler option for my 53131A. Unfortunately I realized once the last of the parts I needed finally got here that the MB510 I bought seems to be a fake, it's a narrower SO8 than the correct part and installed on the board I see a signal going into it but nothing coming out. It's an obsolete IC so not a lot of options other than various China sellers, anyone know of one who sells the real deal or a more readily attainable modern replacement?