Running a 29r up front was all the rage -ok, some people did it. Back in the day, the idea was getting the benefits of a larger wheel up front (rolling over things) and the snappy acceleration of a 26 inch wheel in the back. It slackened the front end, which wasn't all that terrible. Some times.

What is not common at all is to throw a 29r fork on a 26er frame and run 26 inch wheels front and rear. That is... unusual to say the least.

Also, "custom" paintjob but you can see the old decal outline under the new paint? That sounds like the frame wasn't prepped at all.

As for the parts, 29r fork, 170mm cranks, Race Face Deus headset (nice one but out of production for several years)... it sounds like someone went through the online stores picking the cheapest parts available they could bolt onto a frame. I'd walk away frim this one.