Looks like one of the nicer ones.
I could not recommend something for which I do not have the precise specifications. This is what I can see and deduce from the pictures, with the devices numbered in the order they are presented:
- Numbers 3 and 4 seem to be more robust because they have their LCD PCB secured on the mainboard with bolts and spacers.
- Numbers 1, 2, 5 and probably 4 come with unknown chip (probably an m168) in TQFP package, and with ISP socket.
- Numbers 1 and 5 do not seem to have a crystal time-base, which is required for the time-depended measurements accuracy.
- Number 5 with the LiPo battery has an on-board DC-DC converter, that might increase electrical noise.
- Number 4 is called 'M8 transistor tester' (because of the mega8 it possibly has on board?) Is the chip in PDIP or in TQFP package? Does it have a crystal time-base?
- Number 3 has a mega328 in PDIP socketed on board and runs a firmware that seems to be more recent than the other ones. The m328 can be removed from the socket and be updated with an AVR ISP and a breadboard.
[...] So, the bloody thing is as deep as it is tall.
So, trimming the pins and insulating the LCD PCB might work.
But, what the reprogramming is good for if the chip is not an m328?
EDIT: By the way, I should warn you to be careful with the AVR Fuses because a wrong setting can brick the chip and its revival can be from difficult (by the injection of an external clock) to painfull (by desoldering and HVPP with a special HV programmer, like the ATAVRDRAGON).
-George