On 10/03/2019 16:06, N_Cook wrote:
RIFAR540
RD6416 N
Could be 1 instead of I , and N probably refers to the plastic
encapsulation. 14 pin IC in the power supply section of some 1979 kit.

Until I can power-up probe/explore trackside, my guess is perhaps , from
the "16", a variant of CMOS quad analogue sw.