The MK IIa Reference 072/001 was introduced around the year 1963. Due to the missing date in the caseback, this is just an estimate. The biggest difference to the MKId are new dial variations and the unique caseback with the seapearl.
| Reference Number | Serial Range | Watches produced |
| 072/001 | 601.5xx – 601.9xx 617.1xx – 617.5xx | approx. 1.000 |
Case
Stainless steel EPSA compressor case with bajonet lock.
40,2mm x 49,3mm without crown, 13,5mm thickness, lug width 20mm
Bezel
The inner tachy scale of the MK IIa is found in white and grey and with the word “Tachymetre” and starting at 300. Early ones in the phase of transition I have also seen without “Tachymetre”
Enicar Sherpa Graph MK II “tachy 300” bezel in grey
Dial
In the range of the MK IIa you can find a white dial, a white-silver dial, an all black dial and the most common dial in this reference made in black and silver . The Enicar logo is now the small one, above the word Enicar. The lume on the dial is made of Tritium.
Sherpa Graph MK IIa black and silver dial
Hands
Minute and hour hand are formed like paddles. They are not painted and have a tip at the end. The tips are not painted too. We see the is longer tips like on earlier reference.
The second hand is red painted and straight. It’s slightly longer than the dial and floats over the bezel.
The subdial hands are painted black or unpainted. Minute and hour counter hands looks like little arrows, second hand is just straight.
Crown
The MK IIa has one of the older, thin compressor crowns, but with Saturn on it. They are way smaller than the ones of the later references.
Measurements: 6,25 x 2,65; Tap 12
Enicar thin compressor crown with saturn
Back
The back shows the seapearl logo. This you just will find on the MK II references.
Movement: High quality Valjoux 72 with golden finish.
Enicar 101 