Need help finding opposite-hand caliper brake options

[RPS]

I'd appreciate help finding opposite-hand brake calipers for a special project -- much like those used on some time trial bikes to place the calipers either behind the fork or in front of the seat stays.

I’m aware of the Oval for time trials (picture below), a couple of Japanese-market-only calipers, and one for a recumbent so that the brake cable drops in on the left side of the front wheel to miss the chain.

I’d prefer a mirror image standard-style single- or dual-pivot caliper, but appreciate any relevant information. Also prefer brakes still in production.

Thanks in advance for your help.

[RPS]

since it's looking like an Oval Concepts TT brake may be my best option, have any of you used one? If so, do you have any feedback?

Looks like Ulrich may have used them (picture below) during the Tour. Not being familiar with these, I’m a little concerned with the backing plate on the front which looks to be a Tektro; and from the pictures it appears considerably longer than that of the rear.

Are the different backing plates to adjust reach so it can be mounted behind the fork? Any feedback on Oval brakes or products?