I've got a pair of 510 sleuths for plodding about in off the bike. Is there anything similar out there with an spd fitting?
Five Ten District are as near as you will get to the Sleuth
Sport Pursuit have some Chrome SPD type shoes that are casual Converse looky-likey. They are quite stiff though, an actual cycling shoe as opposed to a trainer with SPD.
Be careful with sizing though, they say to size up 1 whole size, I’d suggest up 1/2 a size.
Spesh do some - got some myself down at our cravan. Great for pottering about if you are a clipless freak like me. Can't ride without them.
I wear five ten districts to work in an office* sometimes. They look fairly normal.
Adidas also doing Gazelle SPD's now.
*Albeit a pretty casual office.
Vans used to do some, I’ve still got mine around somewhere. I took the clips off and found some thick rubber, cut it to fit the space in the sole and glued it in, and wore them with my flats. Very stiff sole, perfect for flat pedals.