firmware for wbm760a

Hi

Is there a firmware repositery somewhere that I may search for

I am looking for firmware 7.1.98 for arris wbm760a

I have the following file: TS0705125_062314_NA.WBM760_CM820.img

some of our modems have 7.1.98 and I can upgrade them

but some of our modems have 3.2.48 and refuse to upgrade to this firmware

so I want to try jumping from 3.2.48 to 7.1.98 and then to 7.5.125

or If someone has another firmware in between that I could try

Thanks

Patrick