There are different possibilities in replacing an ECL86:
A PCL86 will work but needs a higher heater voltage.
If your are not interested in keeping the radio original you could try to replace the two ECL86 with an ECC83 and two EL84 including a lot of soldering and I guess unwanted modifications. Also keep in mind that the required heater current will be quite higher in this case.
Another idea is replacing them with ECL82 which are older, have less output power and a different pinout but: this tube usually lasts much longer than ECL86.
If the SABA chassis is handwired it might be worth a try.
Just to mention: I never tried some of these ideas out because I usually avoid radios with ECL86 which I absolutely don't like
