We always had lots of framed and mounted/unfarmed work for sale and I never bought anything in framed, ever. I could always say to a customer "It's going to look something like .... THAT"
If I remember right though, you have a clause preventing you selling goods, unless made to order, so props is the way to go.
I did have a few props as well though, I bought an England Rugby short from JB sports, printed off a photo of Jonny Wilkinson from the internet, plus a ticket, signed those and the shirt "A. Rugbyplayer", framed it all, no expense spared. It won a LOT of shirt orders, plus many wanted to buy it, thinking it was signed by Jonny Wilkinson. One guy, when told it was a prop told me he wasn't a prop, he was a fly half.
There was a printed explanation of how we mounted shirts and it all ended with "this framed shirt is not for sale" but people don't read things, incluiding opening hours!
I had a a set of trinket boxes on shelves within a slipover frame, and a spikey sea shell, which I used to challenge cuastomers to see how it was fastened in; no-one ever found the melinex straps. I also had my own medals, with cap badge, tunic buttons and "flash and hackle" Rebate lined in regimental colours. That also won lots of orders and made the order taking process much quicker.
Under the counter I had a laced and mounted piece of needlework, so the back could be shown and the extra materials to make flush at the back. I also had a platform mounted photo, a mounted encapsukated postcard showing both sides and other mounted things, to show the methods. It saved long boring technical explanations and impressed people who thought it must all be done with sellotape, and even more, those that understood and wanted, conservation.
If I were you I'd have things that look great (duh) but also show things you may get push backs on, like a sports shirt, like anything that could be classed as an upgrade, deep wrappd bevels, slips, mount decoration, 8 ply mounts, bottom weighting, coloured/gilded bevels, etc etc.
The biggest push back I had was always decent width mounts, many people don't even expect a mount - they came for a frame - and when shown a sample will say "Oh maybe just a narrow one then" - IMO (and generally) anything under 3" looks nasty, all my mount samples were 4" bar about 70 washline samples which were 5 - and there's something worth learning too! "Nobody" does them any more (and before anyone says "but I never get asked for them" - well, nobody ever asked me for museum glass either, but I still sold plenty!) . So have good wide mount widths, a good idea is to ftrame a square image, then you can make a set of small, square black frames (everyone wants "just a small black frame") - one an inch bigger than the image, one an inch and a half, one two inches - put them around the image in turn - see if customer still wants that.
Several of these things can be put in the same frame, have the insides easily accessible to show any unusual mounting methods or lacing etc.
