The only episode not to have the noughts and crosses end credits.
They just used a picture of Sergeant Major Zero dressed up as Santa Claws.

Adam, there is no way this ep goes between Ma's Monsters and Two for the Price of One

Why not?
I know this list isn't an official order but not all the orders are right,

example the first four eps in the production order are
Expect the Unexpected Part 1
Expected the Unexpected Part 2
Gold and
Thunder-Roar
And we all know Thunder-Roar must come straight after Expect the Unexpected Part 2

And in the transmission order
Ma's Monsters was ep 26 and
The Sporilla was ep 38
and Ma's Monsters is a flashback ep featuring The Sporilla

Because its obvious Ma's Monsters and Two for the Price of One are a 2 part story, Two for the Price of One even has a recap of the previous ep.

This ep is also the only ep not to have the regular end credits music on a UK broadcast (the song I Believe in Love replaces it)

It doesn’t matter if the episodes aren't together, it didn’t say it the end of Ma’s Monsters “To Be Continued” like at the end of Expect the Unexpected Part 1.

They can be a number of episodes apart and not cause problems to the series, just as long as Ma's Monsters is first and Two for the Price of One is the first It-Star episode.

I mean Lunaville 7 and Crater 101 aren't together and Crater 101 is like part 2 of Lunaville 7.

Ah, but Expect the Unexpected part 2 doesn't have a 'to be continued' caption either, yet Thunder Roar has to follow straight after it.