By the start of 1944 production of the AYD-3 had either ended or was about to end. In January 1944 the US listed the AYD-3 (AN/ARN-1) as an interim Navy set (pending more AYF's replacing it) . Earlier versions of the AYD were noted as obsolete.
Manufacturing companies. AYD - Belmont and RCA. AYF - Seems that bulk was RCA but mention is made of Detrola, REL and Continental but all the latter possibly for a version that was cancelled.
I have now found "Handbook of Operating Instructions for* AN/APN-1, *AN/APN-1A and *AN/APN-1B Aircraft Radio Altimeter Equipments". (Versions of AYF). It is in the UK TNA Air10/3403. Like most TNA files it is not online.
US Ref AN-08-10-213 and UK AP number. AP2582A. Dated November 1943. A joint publication but seems to be primarily a US document, unsurprisingly.
For the AYD (AN/ARN-1) I have AIR10/3250 "Radio Altimeter Equipment AYD Series 2nd Edition" May 1944 AP2533A.