So quick update, I had a look yesterday, removed the rubber boot and checked all was well. All secured, nothing loose.
Undid the two 8mm bolts that hold the metal guide in place, put car in 1st gear with engine running. Moved metal guide snug against the white plastic reverse lockout and tightened bolts. Because I gathered that this is where the issue was, and it needed to be guided snugly into 1st.
Took me a few attempts to make it perfect but I got there, ended up moving it off the white guide a fraction just to help with any movement. Greased it all up and away we went.
Happy days. Thanks guys for the advice, much appreciated as always.