"I nor anyone can hope to guess what would have happened to my Dad had the war gone differently" - Gnome

Let's see now Gnome:

1: Hitler gets his War according to plan in 1938
2: Czechoslovakia is invaded and taken over in 1938
3: Hitler gets his hands on the Czech armaments industry
4: Hitler attacks Holland, Belgium and France and defeats them using the same plan as was used on 10th May 1940 (Oddly enough Gnome the same plan as devised by Schlieffen in 1905) - The results most certainly would have been the same most likely within a shorter time scale.
5: So in 46 days or less, Hitler is standing on the cliffs of the Pas de Calais looking through the white cliffs of Dover - only this time there are no radar masts, and no Spitfires. There has also been no "Miracle of Dunkirk" the Germans have the entire BEF "in the bag" ( A fate its 1914 version did not share, under the bumbling and incompetent leadership of Sir John French and Douglas Haig - they managed to keep their BEF fighting against superior odds didn't they Gnome).
6: Germany through air superiority defeats Britain in the Battle of Britain and having no army, or equipment to defend itself in the event of a German invasion Great Britain is forced to ask for terms.
7: After a short period of consolidation Hitler puts into operation his attack on Russia, to get there of course he must get rid of the minor inconvenience that is Poland. Poland, who were perfectly happy to grab bits of Czechoslovakia, have no allies and are surrounded by enemies Germany, Hungary and Russia. As happened in 1939 Poland is overrun and defeated by Germany, Russia and Hungary in one month and five days - Poland is no more.
8: Your Dad Gnome cannot get to Britain (No point) has the following probable avenues open to him:

a) He gets killed by the Germans either in the attack or during the ensuing occupation
b) He gets killed by the Russians in the attack or during their occupation (That was the fate of quite a number of Poles)
c) He survives to work out what would be a fairly short life as slave labour for the Germans.
d) Escapes to somewhere else either to be killed as the Germans attack Russia - but Gnome is born, if ever, elsewhere.