It was sold to us with 800 lbs as the weight, which seemed light... but I didn't expect 1500 lbs! On the bright side, that was WITH the propane tanks and with all dishes/pans... but it's still heavier than we had hoped. Our Subaru is rated to tow above 1000# ONLY with brakes on the trailer. The trailer has no brakes.
How can/do I go about adding brakes to a vintage trailer? Here's a view of the axle/etc:

Can I add brakes? Is it something better left to a professional, or can it be handled by an eager amateur? We do a LOT of mountain camping, as we live in Colorado, so I'm thinking electric brakes will be best. Any and all help is so appreciated!
As an aside, it towed beautifully this weekend up in the mountains. No problems coming down the passes/hills, etc... but that could be because we have a standard and know how to drive it in the mountains!