Graham,
It’s possible that the over-centre spring fitted to the Peco points is too stiff to allow the Tortoise to operate it.
Assuming you’ve tried sliding the fulcrum thingy up & down, and it doesn’t help, two options:
1 remove over centre spring or reduce preload. Depending on the era of your points, it will be a little hairpin under the weird box thingy at the tie-bar end, or it will be a moulded lump on the tiebar which has to “pop” over a similar lump on the adjacent timber. The wire ones are easily removed, the moulded ones need to be judiciously customised with a scalpel. But beware, it is possible for the switchblade heels to come out of the closure rail fishplates if you’re over-ambitious! This can be remedied by addition of some plasticard, without the lump.
2 fit heavier gauge wire in place of that supplied. This won’t overload the tortoise, but you will likely have to enlarge the hole in the black thingy that goes from side to side, and in the fulcrum. It does have the disadvantage of reducing the travel of the black thingy. This means that the inbuilt switches may not fully switch, and they may then be subject to early failure. Microswitches, or a relay & diode, can be fitted if this is an issue.
Atb
Simon