Those relays are quite "unknown" even if produced and placed on boards like those types. As for a datasheet, possibly does not exist as for being released by the company itself or someone that actually took one of these apart and displayed the info shows no reasonable sign of this.
For the relays foot print on the board for whatever the type, datasheets containing the pin out on many types of other brand relays could be used to find an equal to relay. Then it's whether or not if any found relays are able to be acquired from a source supplier in single or small quantities for any specific type of pin foot print required.
There should be relays available from many other manufacturers that meet the set up unless those Phoenix Mecano are odd ball configured on the pin outs, not likely the case, tho haven't seen the pins from the other side of the board from my perspective to know for sure.
An example of relay types, and their foot print lower down. The list is extensive tho would not list all known relays as for still in development as in obsolete pin types used way too long ago to be relevant for the past 20 or so years, I doubt that board is not that dated.
**broken link removed**
Relays start around page 8-10 and continue on. The foot pin out types are listed to the right of each relay and the relay PDF for that specific type of relay listed per model.
Notes. a relay with a slightly higher coil voltage can be used as long as the voltage is above cut in range a 20 Volt relay can cut in at an usual 15 volts at times with no load on its contacts to cause any buzzing with adequate load. A 24V will work just as well, many are only typically 15 avg milliampere on the coils, and the contacts are usually rated fair on inductive / capacitive and resistive loading to work in place of others. In these cases Inductive loading.
And with proper inductive use the relay should act as a brake on shutdown to remove inductance from the motor to cause an abrupt stop. This should be in the Contactor relay class, SPDT type likely.
https://en.wikipedia.org/wiki/Relay
Hope somewhat helpful.