It looks like a kludge fix zeddy judging by image 6. Also it has what looks to be a black ZX80 PSU which would be consistent with being an early one.
https://m.ebay.co.uk/itm/SinclairZX81-P ... %7Ciid%3A1
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA