I’ve had a good read through the images you posted and I’ve jotted down some notes which I hope may explain/clarify things. Please let me know if there’s something specific which I have missed and you would like more information about. I’ve listed my comments under the heading of each image name, so they aren’t necessarily in chronological order.
Service and Casualty Form. As you are probably aware he joined up when he was 18. The terminology for the period of his engagement “duration of embodiment” means that he joined as a TA soldier. TA soldiers had to be embodied by Royal Proclamation before they could be called up. On the right side of the page we see the first mention of him joining the Special Force Unit which appears to be categorsied as X (1). As I explained previoulsy the X list was used to desiginate soldiers who were not attached to an established unit, either because they were in transit or sick or on long course of instruction etc. The X(1) list comprised all ranks posted to fill vacancies in authorised War Establishments of a Headquarters or an extra-regimental unit (such as a base depot, school etc). But that is all I have been able to discover about this unit, or ME 33 which may be related to it. Further down the right hand side there’s a listing of his medical categories. A1 means fully physically and mentally fit, and trained for employment at home or overseas. A2 means physically and mentally fit, but requires some further training. The dates given relate to his time in the Royal Artillery, but it’s not clear why he might have been downgraded to A2 at this stage.
Military History Sheet. I’ve already covered much of this page in earlier postings. Just a couple of things to note. The first two entries are signed off by the Infantry Records Office, Edinburgh. This almost certainly means that when he first enlisted and was sent to 63 PTW, he had joined the Infantry, probably earmarked for a Scottish Regiment. However within a couple of months he had been transferred to the Royal Artillery. He was with the Royal Artillery for just under 9 months, firstly with 4 Field Training Regiment RA at Maidstone, Kent then 147 Field Regt RA at Larkhill (details extracted from Service i). The reference to LIAP has already been explained.
Service 1. This is listed here out of chronological order. It deals with the end of his Army service. He’s with B Company 1 Holding Battalion and posted to the Y list, category 7. The Y list is for soldiers who are no longer effective for one reason or another. In his case this is because he is getting ready to be discharged. He is going out on Class B release. Class A was for all normal demobilsed soldiers and the date they left was determined by age and length of service. Class B was for men specially identified as being necessary to help with civil reconstruction of Britain (see press cutting below). The W(T) reserve referred to “all soldiers whose services are deemed to be more valuable to the country in civil than military employment”. The (T) refers to the fact that he was in the TA. He still retained his liability for recall to active service at any time. However as can be seen from the next entries he was in fact only called back for refresher training in 1951. The indistinct rubber stamp at the bottom of the image is his PULHHEEMs assessment. This is a medical assessment for various factors which is explained in this Wikipedia article:
https://en.wikipedia.org/wiki/PULHHEEMS The final box shows he was FE which means he was found fit for service “Forward Everywhere”, ie he could be called on to fight in the front line if necessary. This entry is dated 1957 and could in fact mark the end of his service commitment. He would have been aged 32.
Service and Casualty Part II. The crossed out part at the top of the page reads “SOS unit [4 FSU]to MEF [Middle East Force] – Change of command to GREECE wef 31 Mar 1946”. This ties in with your comment about him serving in Greece. However since it is crossed out, I assume that the next entry is what actually happened, namely the process of demobbing him was about to begin, as he had been selected for Class B Release.
Service and Casualty Part III. The rubber stamp entry is pretty illegible in the photo but probably says ?? Coy ?? Holding Bn TOS This unit ex overseas”. Presumably this is B Coy, 1 Holding Bn already referred to. He’s then posted to the Ylist category 7 as already explained above, along with the statement about the W(T) Reserve and Class B Release.
Service i. I’ve already covered most of this earlier. Just to note that 63 PTW appears to have been at Maidstone.
Service ii. He was granted 9 days priv[ilege] leave. Privilege leave is the normal entitlement for a soldier, but is subject to the exigencies of the service, meaning that a soldier can only go on leave if he is not required for some operational commitment. It appears that he was based at Frome at the time, presumably with his battery. He was then effectively fined 5 shillings (it’s referred to as a stoppage from his pay) for damage he caused to a vehicle he was driving. Fairly standard low level disciplinary matter.