Happy to report that I have one of these installed, and working fine after several months. One of the single post signals I ordered at the same time did however have to be returned after a short time, and was promptly refunded, thank you, Dapol, and since replaced.
Two things - I run them on 9v ac to reduce wear and tear, and the other interesting point is whereas the single ones are operated by an intermittent switch, the junction signals come with a spdt switch which remains on in either position. This is nice in that the switch position actually indicates if the arm is on or off, unlike the single ones.