Glynn have you tried stuffing the ports with something like the expanded foam plugs that many subwoofer companies like SVS package with their products. Something similar should be available. If not you can just start with socks. The PMC 22's from either series look like they would do the trick, also if there is a Reynaud dealer anywhere close the Silver Bliss would fit the bill as it is front slotted transmission line book shelf. All of their speakers are front slotted transmission line by design. Another candidate if the sensitivity is not an issue would be the ATC SCM19. Maybe some of the other UK or EU members will pitch in with appropriate models available to you that I would think of.
Yes did try that and they just sounded awful. I have got some acoustic foam loosely over the ports that help a little. Thanks.