The Age cryptic by LR #20,542

LR is back again! I thought we'd get a month of EM first and LR in February so it was a nice surprise. I had an hour or so to crack through this before friends arrived and our Australia Day shenanigans began. We had friends visit who emigrated from our town in Scotland a few months ahead of us in Dec '08 to Newcastle and they've recently relocated to Melbourne. It was great catching up and seeing how big their five kids had become. We went to the beach, had BBQ snags and burgers, came back home and the kids played Minecraft and Halo while adults talked comic books, watched tennis and then played Coup.

About the puzzle (before I warble on more) I got through the top half with little trouble and found the Back To The Future theme after 6 clues solved which was great. I felt I was in my comfort zone knowing all about those movies. The bottom half took me a lot longer and was more solving bit by bit. In the end I was missing half of 27A thinking it was a theme clue and not being able to figure out the right BTTF phrase. It wasn't a theme clue. I didn't figure out the answer and as I predicted on Twitter, kicked myself. It's frustrating to come that close to a full complete puzzle and fail! Ah well. Here's the big pic:

Here's a legend for my scribbles:

Definitions are underlined
Actionable signposts or words are circled
Anagrinds are in rectangles
Anagram fodder has a squiggly underline
Dashes above letters are beginning/end letters or odds/evens 
Underlined numbers are not fully parsed unless ticked and circled numbers are ones I share with my crossword learners club.

What I'm missing bits on are:

13A - Puts an X on model - the angriest (8)

Answer is CROSSEST and I get that the "X" = CROSS but not sure why "model" = EST unless it's using the abbreviation of established which doesn't mean model to me. What am I missing?

16D - Be keen to go inside tenth US embassy (7)

Answer is ENTHUSE and I get that the end is using the US from the clue with just the E for "embassy" but how does the "tenth" fit...nevermind!! I see it's a hidden word now. damn I hate when this happens!! I missed the obvious signpost of "inside" but couldn't figure out why the second "T" was missing from "tenth" blarggg.

19D - Studs put working into glutes (7)

Answer is BUTTONS and not BOTTOMS which I had in place and I had guessed from "glutes" as the definition and put in the sidebar. I couldn't understand how we get there from the clue. All I can see is a "motto" in BS. I was thinking studs are wall supports, sexy blokes, tuxedo button bling, animal husbandry. Confession time: I only just now looked at the answers to see I had the wrong one in grid. Now it makes sense that "glutes" = BUTTS and "working" = ON and we put ON into BUTTS to get the tuxedo shirt bling definition. Again, I couldn't solve this until I typed it out...and paid closer attention to the answer key. Damned sneaky!

Hoping your Australia Day weekend was great, too. I'll pay closer attention (ha, not likely) to clues. If anyone wants a clue or element explained in more detail just ask in comments and I will do my very best to comply. 

LR makes me look forward to Mondays, which is quite an achievement for anyone. Even if he does set traps that I skip gaily into all the damn time.