Browse data on old machine's HDD, without booting machine or removing HDD?
You can boot each older laptop into Target disk mode by holding down the T key at startup. The older laptops need to be powered up. This will present the internal HDs on these older laptops as an external HD on your MBP.

Both of these older laptops have FireWire 1 ports, however, so a physical connection to your current laptop is problematic as you will have to connect a FireWire 1 cable to a FireWire 1 > FireWire 2 adaptor, then connect that to a FireWire 2 > Thunderbolt adaptor to your MBP.

This may or may not work, but I used FW1 > FW2 adaptors for a few years without a problem.

If either or both of the older laptops do not power up, then removing the HDDs from within them will be necessary.